Win 32 Services

I'm not even sure what topic to ask this question under. Running XP Home, all
up to date. When I try to open something like My Computer or a file of
thumbnail pictures, I get the error message "Generic Host Processes for Win
32 Services has encountered a problem and needs to close" and it then asks if
I want to send the error to MS. These screens take a long time to open and
for example the Properties of the hard drive shows no occupied volume on the
drive. Other than these annoyances, everything else seem to run, after
closing numerous error messages. I have rebooted and the problem persists.
What are the Win32 services and the Generic Host Processes and what can be
wrong?