Hi,
System Restore monitors a core set of file types along with setting and
most of the registry. What happens is when a system is restored back to
a point before an application was installed only the unmonitored files
will be present, and monitored files will be gone. This will cause the
application not to function and may cause it's reinstall to also fail.
The best practice it to uninstall any application installed after the
restore point being restored to.
List of Files and Folders System Restore Monitors
http://bertk.mvps.org/html/filesfolders.html
I would suggest undoing the restore just performed, uninstalling the
applications in question, then performing the original restore. Then
reinstall the missing applications
All About System Restore in WinXP
http://bertk.mvps.org/