Try initiating System Restore in "Safe Mode with Networking" reached by tapping F8 while booting up.
I don't know what operating system and service pack this is but System Restore is normally found under Start/All Programs/Accessories/System Tools or you can invoke it through Start/Run and type in rstrui.exe and click Enter or OK.
If that's successful that would be all you need to do except temporarily turn off System Restore in order to delete the infected restore point.
If not try downloading Malwarebytes Free, update it and run a full scan with it, all in that mode: http://www.malwarebytes.org/products/malwarebytes_free
Make sure it's only the free version, do not click the option for a free trial. It will do all that in that mode.
I think the only solution left would be to use System Recovery Options.
Here are some Tutorials (also some other links at the bottom of the first post in the 7 and Vista ones)
XP: There are many articles on this so I am just publishing the search results HERE
This virus seems difficult but is relatively easy to get rid of. Follow the steps below:
- Reboot your PC in safe mode (tap F8 while booting and select option Safe Mode)
- Go to Start -> Run
- Type 'Msconfig' and hit Enter
- Go to Startup and disable every option
- Reboot your PC
The virus will not start up anymore. it is, however, still present on your PC. No big deal but you can remove it.
- Go tot Msconfig as mentioned above.
- enable the first option and reboot
if the virus stays away it is not present in this option and you can leave it enabled safely
repeat these steps for every option. As soon as the virus reappears after reboot you know in which option the virus is hiding. Just delete the directory in which it is present and the virus is gone.