"Windows Installer" pop up appears chronically

"Windows Installer" pop up appears frequently without reason. Says "preparing to install …" while nothing is installing. I can cancel, but sometimes it slows down other processes. This seems to have started after I upgraded from Office 2003 to 2010. When opening a Word document I need to cancel "Windows Installer" pop up, then cancel "Office 2010" start up, and reclick document, which will then open.

I thought this might be a malware issue and sought help on the Safer-Networking forum. Some issues were solved in that forum, but I was then referred here for assistance with this issue. Following is a link to that forum thread:
http://forums.spybot.info/showthread.php?t=59953

Thank you for any assistance.

I suggest you have a read here: http://support.microsoft.com/kb/2438651/en-us

Now that I've looked at your logs… I suggest you have a read here also: http://support.microsoft.com/kb/950683

How do I find the System Root Directory to delete those files generated by the Visual C++ install?

They're all in the root of your C:/ drive.

On your desktop - click on My Computer icon
Then double click on your C:/ drive

The next window that opens should show you everything in the root of the C:/ drive. You should be able to identify those files and then right click on them and select delete.

Be Careful… Don't delete other files.