if your mouse is moving but you are not able to interact with anything, it means that explorer.exe has hung. Its the program that allows the user to communicate with the operating system.
Usually this is indicative of a 3rd party program (some extra program) that is interfering with explorer's normal operation. the solution is to turn off everything that starts automatically when the computer is turned on. as a side effect it will also speed up the operation of the computer. (Essentially, this is what computer repair stores will charge you $50 bucks an hour to do)
here is what you should try
- Restart the computer in safe mode (if you don't know how, go http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode")
- log in using an administrator account
- open msconfig (if you don't know how, go http://netsquirrel.com/msconfig/msconfig_win7.html" )
- navigate to the startup tab
- un-check everything except for your anti-virus/anti-spyware software. you don't really need anything else running all the time other than security software.
- apply, reboot and test system.
hopefully that resolves your problem.
if you don't know what the item in the list is, then i suggest you simply Google the name of the program and try to find out what it is, then based on that you can decide if you want it running ALL the time (checked) or you will run the program manually when you need it (unchecked)
to recover from a hang try to open the task manager using the keyboard shortcut
CTRL+Shift+ESC (hold down in that order)
if the task manager opens, then switch to the process tab
find explorer.exe and kill it
then click File>New task
in the window type in explorer.exe and click ok
if my initial assumption of the issue being a rogue 3rd party program causing the issue, this should resolve it.