After doing a format and restore (using a program that preserves time stamps
and short file names) of a Windows XP partition, the first instance of any
windows upgrade or driver upgrade (or re-isntall) will end up deleteing all existing
files and folders in

\Windows\Installer

After this occurs, if I restore \Windows\Installer from the backup a second time,
using drag and drop via explorer, the problem is solved.

The same problem exists in Windows XP 64 bit version.

The workaround I use now is to do the restore, then reinstall my video driver,
which results in the purge of \Windows\Installer, then restore the Installer
directory a second time using drag and drop.

Anyone here have any ideas what is doing this or why \Windows\Installer directory
woudl be purged? Is it related to time stamps of directories?