When i open a word document saved in "My documents", another word documentwith the same title appear. For example, if i click on the file named "me", another file with the name "~me" appears.Then, when i close the "me" file, "~me" dissapears. What virus is this and how can it be cured? I have also scanned my computer with AVAST, but the scan could not detect any infected files. thank you.

This is standard behavior for many Microsoft products. Not a virus. If you don't want to see that anymore, just open up the window for, let's say, My Documents, then tools > Folder Options> click the view tab, then scroll to hidden files and folders and click "Do Not Show Hidden Files and Folders"

The ~me file is a temporary file created by Word while you are working on the me.doc file. As "gooogle" noted it is deleted when you close Word. This is normal. The ~me file is also used by Word as a backup and recovery file in case your computer crashes while you are working on a file if you have "Save auto recover" checked under Tools>Options>Save in the options. Be sure to set a time. I use 10 minutes. That way you will only lose the last 10 minutes of work.

Thank you all for helping me.I kept on scanning my computer because i thought it was the "brontok" worm. So, again, Thank you!