Windows 7: double clicking a folder opens a command prompt

dear sir,
till yesterday. it was ok. since today morning, this problem appears. when i double click a folder to open it, it asks for permission to open with windows command processor. if i click on yes, a command prompt appears and commands keep on scrolling. if i right click on the folder, then the first option that comes is "take ownership". i am using microsoft security essentials. i have scanned with that as well as malwarebytes antimalware but the problem persists.

Can you remember if you did anything just before the problem started? Download/install a new program? Install Windows Updates? Change any computer settings? Go to a new website you've never visited before?

You can try using a restore point that goes back to before the problem started. Be aware that a system restore will also uninstall programs that were installed after the date of the selected restore point.

System Restore

It appears your folder association settings are messed up. See the following link for a fix.

http://social.technet.microsoft.com/Forums/en-US/w7itprogeneral/thread/f4392db2-dbc2-4f74-b533-3777144e1a06/

The fix is in the zip file posted by Ramesh Srinivasan and can be downloaded from;

http://www.winhelponline.com/temp/w7-folder-reg.zip

Generally I would not suggest downloading a zip file, but I am very familiar with Ramesh and am confident the download is safe.

HTH

i had installed windows updates, installed avast antivirus, antimaleware. i have done a system restore but it could not be completed. an error occured. i will post the error code soon. as of now, the problem prevails. i have done a real time scan, boot scan with avast. installed the registry editor published by ramesh sir. no change as of now.