Here try uninstalling it this way
Hopefully it will work for u..
Here is how you completely remove call of duty from your computer.
Step 1:
1) Click Start button > Run.
2) At the prompt type: REGEDIT. The registry editor will open.
3) Click the "+" next to HKEY_LOCAL_MACHINE.
4) Click the "+" next to SOFTWARE.
5) Click the "+" next to ACTIVISION.
6) Right-click on the CALL OF DUTY folder and select Delete.
7) Close the registry editor.
Step 2:
Once the registry keys are removed, we'll need
to remove the game files from your hard drive. These instructions assume you've
installed the game in the default directory.
1) Double-click the My Computer icon.
2) Double-click the C:\ drive.
3) Double-click Program Files.
4) Right-click on the Call of Duty folder and select Delete.
Step 3:
Remove the COD.INI file from your hard drive.
1) Click the Start button > Find (or Search) > Files & Folders.
2) Search your C:\ drive for a file named COD.INI.
3) The file should be located in C:\WINDOWS.
4) Delete this file.
5) Reboot your machine. At this point the game is completely removed from your
system.