I recently upgraded my system at work from Windows ME to Windows XP Professional (holding to my policy of waiting for the first service pack to be released before changing operating systems). I've been greatly impressed so far with the OS; no longer have to reboot 8 times a day ala ME.
I did a clean install per your past recommendation which went without a hitch. However, we just purchased another computer preloaded with XP and rather than redownload Service Pack 1 at work again (we're on IDSL) I downloaded the full network patch at home via my cable modem and then burnt the file to a CD-R. So far so good...
However, when I got to work, my system would see the contents of the CD-R but when I tried to copy off files, it gave me an error message to the fact that the data was corrupted and halted. Curious, I tried the CD-R on another box running Windows 98 and everything went fine. After thinking for awhile, I tried checking to see what settings were present on the CD-ROM under Device Manager. I finally discovered the problem after searching for "Windows XP CD-ROM DMA" and found the following MS article: http://www.microsoft.com/hwdev/tech/storage/IDE-DMA.asp
It seems that Windows XP by default puts regular CD-ROM drives under "PIO" mode; once I made the switch to "DMA if available" (see the article for instructions; the option to use DMA is no longer on the CD-ROM entry in Device Manager, rather under IDE ATA/ATAPI controllers), my original CD-R worked fine.
Hope this helps someone out there (before they start cursing at their innocent CD burner...)