Is there something different about your operating system, such as files and folders having been moved to another drive?
Have you done a disk cleanup lately?
Also what OS and service pack if appicable is this?
Mcafee Total Protection wasn't updating so I removed it and tried to reinstall.
OS is 64 bit Windows 7 service pack 1.
Try running a disk check to see if this is caused by disk-read errors, I recommend a chkdsk /r which fixes errors, see the Tutorial here: http://www.sevenforums.com/tutorials/433-disk-check.html
But before doing that do a Disk Cleanup: http://www.sevenforums.com/tutorials/818-disk-cleanup-open-use.html
I'm reading online that this is often caused by lack of virtual memory so the above steps should help.
I tried your suggestions of cleanup and chkdsk and I still get the same errors. I have 385GB free on my 500GB hard drive.
Any other ideas?
None that I can think of right now, sorry. Technical Support is available for free by phone or online chat 24/7, they may know better.
It's linked under Useful Links at the top of this page.
I just realised you had trouble with contacting support.
Something is drastically amiss here. Run Malwarebytes Free and maybe AdwCleaner then I would post a Hijackthis log on the recommended forums lower down the last link in my signature below.
Something else to read as this could be your problem: http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_programs/down loads-try-to-install-to-wrong-drive/33d4ae3a-ef40-49f5-9cf2-0c520695a13e
OK it may not be the same OS but the principle may still apply.
My registry entry is correct as c:\program files. This seems to be specific to Mcafee products. I have no problem installing other software.