OEM Service Release 2: Hard To Get, But Worth Having

   With Windows 95 out for just over a year and rumors of "Windows 97" flying, Microsoft quietly introduced a new version of Windows last fall that has generated a lot of attention.  They call it OEM Service Release 2, or OSR2 for short, but so many things have been improved that Microsoft could have as easily called it Windows '96 it's as big a leap in its own way as Windows 3.1 was over 3.0 five years ago. 

The Upgrade Debate
   The first thing to note on OSR2 is that it's only available if you buy a new computer, or at least a new motherboard, and support is provided only by the seller, not Microsoft. That's why we're giving it only 3 stars – it's not available as either an upgrade or as a full version for sale by itself, and the CD-ROM has been coded so that OSR2 can't be set up on a system that already has Windows installed. That said, there are ways to install OSR2 as an upgrade, and if you're buying a new motherboard or if you get a new system, and want to move the contents of your old hard disk en masse rather than reinstall all your software  upgrading to OSR2 isn't a bad idea.
   Microsoft says that OSR2 hasn't been tested on the same range of existing systems that the original Windows 95 was, and since they had 50,000 beta test sites that time they're probably right. That's part of why this new version is being distributed only to PC manufacturers, since manufacturers can test it on each model and iron out any kinks.  OSR2 is, however, designed to run on any computer that's suitable for Windows 95.
   If you can't get OSR2, you can still download many of its features from Microsoft's Web site.

The New Features
   While OEM Service Release 2 is still Windows 95 at its core, it does include many of the new goodies that Microsoft started developing as soon as Windows 95 itself was complete.
   FAT32: This is the biggest improvement that OSR2 makes, and one of those you can't get any other way. Since the introduction of MS-DOS 3.31 on a few makes of PCs in 1987, DOS has allowed up to 65,536 clusters (represented by a 16-bit number, so this was called FAT16) in a hard disk partition.  As hard disks got larger the size of each cluster got larger, causing a great deal of waste of space because any file had to use a whole number of clusters; if your clusters are 16K each, even a one-byte file will take 16K on your drive and a 17K file will take 32K. Because of this many people have created more than one partition on their drives, putting up with the aggravation of multiple drive letters to get smaller cluster sizes.  FAT16 also limits each partition to two gigabytes, so with today's larger drives you have to use two partitions anyway.
   FAT32, as the name implies, expands the limit to over four million clusters -- the limit that can be represented by a 32-bit number. With this setup you can have a partition as large as eight gigabytes and still have clusters of only 4K.  The partition size limit is now two terabytes -- 2048 gigabytes!
   The only drawback to FAT32 is that such a partition can only be read by OSR2 (or the DOS core that comes with it) and disk utilities that either do everything through DOS or Windows calls or are rewritten to work with FAT32. Among other things, earlier versions of Norton Utilities can't handle FAT32 (though the latest Windows 95 version can); neither can Microsoft's own Interlink Server (INTERSVR.EXE), though Interlink can still be used to allow a new system with FAT32 to access the drives of an older system that doesn't.  A FAT32 partition presently can't be read by any competing operating system -- not Windows NT, not IBM's OS/2, nor Linux -- though in some cases there may be upgrades to allow FAT32 to work.  (Microsoft says that Windows NT won't support FAT32 until version 5.0; conversely, OSR2 still won't support the NT File System, which has the same advantage on NT that FAT32 provides on OSR2.)
   A FAT32 partition can't be read by previous versions of MS-DOS, either, so Microsoft has removed the "multi-boot" capability that lets Windows 95 users continue to use their existing DOS. Fortunately the vast majority of DOS applications work fine with the DOS core of Windows 95, so you can still use older applications either by launching the MS-DOS prompt from Windows or pressing F8 during boot and selecting "Command prompt only" to boot without loading the balance of Windows 95.  The DOS core is now identified as "MS-DOS 7.1."
   At present Microsoft doesn't offer a way to convert existing partitions over to FAT32, though they reportedly did have such a program for beta testers and are expected to include this in the next Windows 95 general release, code named "Memphis." Several utilities from other companies, such as PowerQuest's Partition Magic (3.0 or later), can convert between FAT16 and FAT32

   Bus Mastering: One problem Windows 95 had when it first came out was that it didn't have the right configuration files to support the PIIX (PCI-to-ISA and IDE Accelerator) interface chip used in the Intel 430FX "Triton" chip set, which was starting to appear in new Pentium-based PCs at the same time. This caused quite a few disk-related problems on those systems, and led Microsoft to add this support in the first OEM Service Release in early 1996.  OSR2 builds on this by adding support for "bus mastering" or "direct memory access," a technique that newer IDE drives can use to transfer data while placing a much lower burden on the processor.  This feature also works with the newer Intel chip sets that use the PIIX3 IDE interface, so it can be used with most Pentium systems today and nearly all Pentium Pro and Pentium II PCs.
 

   If you have OSR2 on a Pentium-based system with IDE drives, you may be able to use this feature but will probably have to turn it on first. Go to System Properties, select Device Manager and click the plus sign next to "Disk drives."  Select one of your IDE drives and click Settings, and you'll see a screen like this.
   If you see the "DMA" box as shown here, check it, then close everything and restart your system. (If you have an ATAPI CD-ROM drive, you may find a DMA box there too.)  This will enable bus mastering, which should speed up many applications even though the results may not be apparent on benchmarks.
   Other enhancements to the file system

.include the improved DriveSpace 3 that came with Microsoft Plus! for Windows 95, though it won't work on a FAT32 drive. There's also a safety feature that runs ScanDisk automatically if for some reason Windows wasn't shut down properly the last time you used the system; this helps prevent errors that could cause lost data if they're not fixed promptly.  Another new feature allows you to have your IDE drives shut off their motors after a specified period of inactivity (even if your system doesn't have "power management" capability); OSR2 also supports removable-media IDE drives and the new LS-120 floppy drives

   Improved Virtual Memory: OSR2 has improved handling of virtual memory, and also fixes a bug that Windows 95 had which caused the name and path caches to have the wrong sizes. You can find details on how to fix the latter problem in older versions at http://www.microsoft.com/kb/articles/q138/0/12.htm.

   Display and Multimedia: OSR2 has a wider variety of video card drivers, and a new feature to let you set the refresh rate of your video card if it allows Windows to control it; something possible before only with some cards' third-party drivers. This can be accessed from the Display Properties screen by selecting Settings and clicking the Advanced Properties button.  Normally you'll want to leave this in the "Optimal" setting, but if you run Windows-based games or view motion video files changing it to "60 Hz" may improve graphics performance.  Support is also provided for the OpenGL graphics enhancements, and a set of 3D screen savers is included to show off OpenGL's capabilities.
   Speaking of games and motion video, OSR2 includes a pair of multimedia enhancements for those.  DirectX 2 is a set of features that allow Windows games to use graphics and sound more effectively, and incidentally includes improved video and sound drivers. ActiveMovie adds playback capability for QuickTime and MPEG-1 video (including Video CDs, with the right CD-ROM drive) and .AU and MPEG Layer I and II audio files.  MPEG is very complex to decode, so you need a fast system to do it; I couldn't get acceptable MPEG audio performance on a 486DX2 system, and even on a 75 MHz Pentium PC MPEG video was rather jerky (though it worked reasonably well on a 200 MHz system).  QuickTime playback is very good, though I found that some files that would play with Apple's player wouldn't with ActiveMovie (though I have no way to know if those files were encoded correctly).

   Internet and Online Services: Microsoft has been pushing its Internet Explorer ever since Windows 95 first came out, so it's no surprise that IE 3.0 is included as part of OSR2.  IE 3 has become a very close competitor to Netscape's Navigator 3.0 as an all-round Internet access program, and has some nice features that Navigator doesn't have (such as the capability, with an add-on you can download, to display foreign character sets even on a U.S. version of Windows 95). One of the best IE features for would-be Internet users is the Internet Setup Wizard, which not only makes it easy to set up a connection to your service provider but shows you a list of selected national ISPs that serve your area and helps you sign up for the one you choose.
   OSR2 also includes Microsoft's Internet Mail and News, another good pair of Internet applications, an Internet phone program called NetMeeting, and Microsoft's Personal Web Server.  (IE and IM&N are installed whether you want them or not; you can delete them if you like, but you have to re-install them first to enable the uninstall feature.  Both installation files are included on the OSR2 CD.)
   After the introduction of The Microsoft Network, which provoked screams of outrage (which turned out to be largely unjustified) from competing online services, Microsoft agreed to make competing services' setup programs available on new PCs.  OSR2 includes the programs needed to sign up for America Online, AT&T Worldnet and CompuServe Interactive.
   Finally, Dial-Up Networking has been improved with the addition of the SLIP and scripting capabilities previously included in Plus! as well as other enhancements (such as an option to automatically dial when you select a defined connection).

   Windows Messaging: This is a slightly refined version of the Microsoft Exchange client, renamed to avoid confusion with the Exchange Server program.  It's been reworked to run faster on systems with less memory, and includes an Imaging application from Wang that works with Windows Messaging's fax feature.

   Old MS-DOS Utilities: This is the one area where OSR2 is actually inferior, because Microsoft has deleted most of the MS-DOS 6.x utilities that used to be found on the CD in the \OTHER\OLDMSDOS directory.  You can still download them from Microsoft's Web site at http://www.microsoft.com/windows95, or get them from a previous Windows 95 CD if you have one.
   One thing that won't work on FAT32 drives for some reason is the INTERSVR.EXE program that makes up part of Interlink; you can still use INTERLNK.EXE to access non-FAT32 drives on another machine. If you need to access a FAT32 drive remotely from another Windows 95 system, the best answer is Windows 95's Direct Cable Connection feature; this works with the same serial and parallel cables used by Interlink.

   Using Plus!: Contrary to some rumors, Microsoft Plus! for Windows 95 works fine with OSR2 as long as you deselect those portions that are already included with OSR2. Choose the Custom Setup option when you install Plus! and deselect DriveSpace 3, SLIP and Scripting for Dial-Up Networking, and the Internet Jumpstart Kit.  (If you don't have DriveSpace 3 installed and want to add it, use Add/Remove Programs to add it from the OSR2 CD.)

How To Spot OSR2
   If you're trying to see if OSR2 is installed on a system (say one you've bought recently), you can bring up System Properties (either friom the Control Panel or by right-clicking on My Computer). The main screen shows which version of Windows 95 is installed, like this:

   If you see a version number of 4.00.950 B, you have OSR2. If it's 4.00.950 A, you either have OEM Service Release 1 or the original version of Windows 95 with Service Pack 1 installed.  If you see 4.00.950 without a letter, you have the original version.
   Another way to check is to bring up the MS-DOS prompt and type VER [enter]. With OSR2, you'll get a version number of 4.00.1111. If you have a program that reads the DOS version number, it will show 7.1 for OSR2 and 7.0 for earlier Windows 95 releases. 

   You can also identify OSR2 from the part number on the Windows 95 CD. In the U.S., if it says "0796 Part No. 000-45234" it's OSR2.  If it has a part number of 000-45236, it's OSR2 with Microsoft Plus! included.  If the date on the CD is either 0196 or any date in 1995, it's an earlier version.  OSR2 is usually sold with a second CD-ROM called Windows 95 Starts Here/How & Why, though some manufacturers don't include the second disc. (Versions sold in other countries will have other numbers.) 
   Also, some manufacturers are selling new PCs with a special CD that doesn't have a setup program; this allows you to access the utilities that are included on the CD, but prevents you from using the CD to install Windows 95 on another computer. (These systems often have the setup program and related files on the hard disk in the \WINDOWS\OPTIONS\CABS directory.)

Beyond OSR2
   Microsoft's next project in the Windows 95 product line, presently known as "Memphis" and referred to by some as "Windows 97," "Windows 98" or "Windows 4.1," is a full-blown upgrade that will be sold to the public, not just installed on new computers.  Our sources and Microsoft's public statements indicate that this will include everything that OSR2 has plus newer versions of DirectX and ActiveMovie, a wider variety of device drivers, support for a number of new technologies such as DVD-ROM, and Internet Explorer 4 which will integrate the browser with the Windows Explorer. Memphis is also rumored to be optimized for the Pentium processor in key areas, making that code quite a bit faster on Pentium systems and only slightly slower on 486 machines.  It's not yet known what the minimum system requirement will be, but IE 4 requires a 66 MHz 486 or faster system with 8 Mb RAM so that is likely to hold for the rest of the package.

For More Information
   One of the best OSR2 resources is Sean Erwin's FAQ, which can be found at http://www.users.cts.com/king/s/serwin/osr2.html.  Some of the information in this story came from the FAQ.
   Microsoft's own Web pages dealing with OSR2 are at http://www.microsoft.com/kb/articles/q155/0/03.htm and http://www.microsoft.com/windows/pr/win95osr.htm.  The latter has pointers to the new components that you can download for previous versions of Windows 95.

-- Ed Ellers