We understand this issue is intermittent, I am going to re-post some successful answers in this thread and group them together. This way users having this issue will not have to dig in this thread to find them:
Solution provided by "HowLuckyCanOneGuyBe"
#1 – remove temp files
Start > Type in %temp% > hit enter > Delete all the files in this folder. up to this point it should already work if not try empty your trash bin too. if it is still not work move on to #2.
#2 – stop windows from caching the thumbnails
Click the Start button, click Run, then type in gpedit.msc
Choose: user config/admin templates/windows components/windows explorer >
look for “turn off the caching of thumbnails in hidden thumbs.db files” >
right click/ edit /choose enable
#1 should already help if not #2 will do.
Another solution provided by "alanomaly"
1) If you use Outlook and the folder contains any files that came from emails, close Outlook - it might be getting in the way trying to keep a link with the attachment
2) Empty the recycle bin
3) Disable folder thumbnails (see sevenforums.com/tutorials/11738-thumbnail-previews-enable-disable.html if you're not sure how)
4) If nothing else works, install and use Unlocker ( softpedia.com/get/System/System-Miscellaneous/Unlocker.shtml )
Another solution provided by "Macintrasher"
Open up Task Manager (ctrl+alt+del) and click on the Processes tab. Look for 'explorer.exe', select it and end the process. This will cause your taskbar and desktop to vanish. Bring up Task
Manager again, then click File > New Task (run). Type explorer.exe and hit enter to restart the service. It hasn't been a permanent fix, as the files get relocked after a short time, but it'll let you delete/rename/over-write them for a little bit.
Because this issue is intermittent and because of the age of this thread, to avoid confusion, I am going to ask anyone who has attempted the above steps without success to create a new thread, that way the community can help them
out specifically. I posted a link below, I hope this helps everyone.
Boot the computer in clean boot and try to open the program. To help troubleshoot error
messages and other issues, you can start Windows Vista by using a minimal set of drivers and startup programs. This kind of startup is known as a "clean boot." A clean boot helps eliminate software conflicts.
Steps to perform clean boot and check if you have the issue.
i.Click Start, type msconfig in the Start Search box, and then press ENTER.
If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
ii.On the General tab, click Selective Startup.
iii.Under Selective Startup, click to clear the Load Startup Items check box.
iv.Click the Services tab, click to select the Hide All Microsoft Services check box, andthen click Disable All.
vi.When you are prompted, click Restart.
vii.After the computer starts, check whether the problem is resolved.