Windows Installer issues - will not install or uninstall anything

Windows Installer is hanging on install/uninstall of anything using
its function. Even trying to install Windows Installer Cleanup hangs up.
I have already run RegistryFix and it had no effect.
I checked to make sure the Windows Installer service is running and it
is.
However any software that uses InstallShield or Wise installer goes in
without problem.

I also looked at Event Viewer hoping to find something but nothing
there looked like usable information concerning why Windows Installer
is hanging up.

Configuration info - Dell C521 with 1GB RAM, 80GB SATA hard drive
running Vista Home Premium and all relevant updates are installed.

It seems to me like another Windows Installer 4 problem but if anyone
has any ideas about alternate possibilities I'm all ears. (And that's
a pretty weird visual). Also if it is a Windows Installer problem, how
do I check for Windows Installer being all there and how to fix it if
it's not.

Searched the Knowledge base and nothing was present for repairing
Windows Installer in Vista. Then I found:

What is Windows Installer?
http://windowshelp.microsoft.com/Win...c2bc71033.mspx

Well I don't know what Microsoft calls "Automatic Repair" but I finally
had to do a System Restore to get the Installer running again.
I would be interested in learning how this "Automatic Repair" works.
System File Checker found corrupt files but was unable to do repairs
and left a 43MB log of its activity. It then left a message to look at
the log to find out what the problems were. However attempts to look
at the log delivered error messages saying I didn't have permission
even though I was on as an administrator. Also what do you use to look
at a 43MB text file?

Anyway you said you would be interested in learning how this turned
out so there it is.