When a computer has a problem shutting down, it usually means there are conflicting programs that are creating the issue.. Start by uninstalling any junk programs you don't use.. For example, if you've got two antivirus programs on the computer, uninstall one... Same thing with antispyware programs that may be running in the background... It's also possible to disable unnecessary startup programs in "msconfig" and in "Services" as well. (Use the "Safe" or "Tweaked" column in the chart.) IN addition, make sure to scan the computer for malware with something like Malwarebytes, Hitman Pro, or SuperAntispyware.. Remove anything they find..

Malwarebytes
http://fileforum.betanews.com/detail/Malwarebytes-AntiMalware/1186760019/1

SuperAntispyware (select the "Free Edition" download link.)
http://www.superantispyware.com/download.html

Next, if you haven't already, clean out all the junk files such as Temporary Internet Files, Cookies, and files in the "Temp" folders.. After that, try running a disk defrag and Chkdsk using the link below. (The article is for Windows XP, but the Chkdsk program is run the same way on Win7.) The disc may have minor errors that can be helped by running both of these tools.

How To Run 'Error Checking/Chkdsk' On Win2000/XP

Hope this helps and let us know how it goes..

Grif