Virus make a lot of changes in your computer. Many times happens that the virus is deleted but its effects are still active.
The solution that is described below can be used to at least restore the access to root drives.
This solve two problems related with these issue. This is going to restore the access to C drive.
1. Press Windows Key + R, type cmd, and press enter.
2. In the command window type c: or the drive you want to restore.
3. Type cd\ and press enter.
4. Type attrib -r -s -h autorun.inf and press enter.
5. Type del autorun.inf and press enter.
Now if you get a File not found message continue with this post if not just restart your computer.
6. Type regsvr32 /i shell32.dll and press enter.
If the problem still persists it could happened that a resident virus was on memory so use an antispy or antivirus solution.