BleepingComputer.com: File Locked By Explorer.exe

Hello.
My girlfriends laptop has Vista installed on it.
Just recently she has been getting an error every time she tries to delete, rename or move files.
The error states that the files is currently locked by another program.
I downloaded an unlocker program. When i run it on any of the locked files it shows they are locked by explorer.exe

I have had her reboot the computer & immediately try to rename or delete the file & she gets the same result.

Also have tried doing this in safe mode. The only way we can get the files renamed or deleted is 1) bringing up a command window, then terminating explorer.exe process & then deleting the files using the command window & using DOS commands, or by using unlocker program.

Yes, we can use unlocker program, but I want to know what may be causing this. this is a new problem. no new software has been installed during the time that this started...

any ideas would be helpful

thank you

Take ownership of file or folder in Vista
http://www.vistax64.com/tutorials
See if this works for you