I am unable to open the hard drive C: D: E: by double clicking. It opens a popup wich asks me to select a program. I guess my computer is infected by a virus. 

Here's how you fix it

Steps u need to follow

1. start->run
2. type - "Regedit" press enter
3. press - Ctrl + F 
4. type "MountPoints2"
5. click on findnext
6. delete the key mountpoint2 and its subkeys. Just delete the root everything under it will be automatically deleted
7. repear the search until all  mountpoint2  keys are deleted

I think UR Problem would have been solved by now

and also make sure to clean the virus the main reason why this happened. use an antivirus , Avast is a good one.