Here's the scoop on the SP2 patch:
It fixes a number of files in the NTVDM
(NT Virtual DOS Machine) and WOW subsytems which allows Windows XP to "emulate" DOS.
Most of these patches as:
**The HP SP2 Patch (either the sticky thread at the top of this Forum or My General Drill Page)
**The FIX Patch that Blsbet Found
**16bitSS.zip
They put back the following files
Command.com
AUTOEXEC.NT
CONFIG.NT
The first patch is the easiest to use because it is self contained.
However, these are not the only files which can be corrupted or deleted in the subsystem by either MS HOTFIXES or Service Packs or SPYWARE or TROJANS, VIRUSES etc.
There are a few more files which if corrupted can cause certain error messages to appear.
You can test you NTVDM and WOW programs to see if they are running correctly by taking a look at
the following articles in:
The General Drill and the articles that is recommends reading.
expecially this article:
Troubleshooting NTVDM and WOW Startup Errors Here are some of the other files which may be missing or currupted and need to be replaced, many of the files you will have on the Original Windows XP CD, but I don't think that they are present on either the Pro cd or Home CD if it contains SP2 but I could be wrong here as I don't have XP Pro or SP2, yet not to worry if this is the case ... I belive that the HP SP2 patch restores all of these files. As many gamers who have used the HP patch and have Pro or SP2 ...once it is applied, many of thier DOS games play just fine.
Ntio.sys
Ntdos.sys
Ntvdm.exe
Redir.exe