Do you have access to another computer to download stuff with, and a flash drive?
Does the sick computer have a USB port?
Download
MBAM (from MajorGeeks - an approved mirror) and save it to the flash drive (usb stick.)
Rename the installer file to something like "Alpha222.exe" and transfer it to the sick computer, then double click it to run it. It will install MBAM on the computer (if it can be installed). Once installed, the default is for MBAM to run and update itself, let it do so. If that all works, run a quick scan. At the end of that scan it will produce a scan report. Select all it finds, and then click "remove selected". If it prompts for restart, do so immediately.
If it can not be installed or run:
Restart the sick computer in safe mode. Start taskmanager if you can, look under "processes" and if "system tool" is present, highlight it and select "end process". Ok your way out of the warning. Then (while still in safe mode) install MBAM - should be no need to rename anything - and run a quick scan. It won't be able to update in safe mode, but it might find the file that's causing the problem and zap it. Select "remove selected" at the end of the scan, reboot (into normal mode), update MBAM and scan again.
Let us know how that works.
If you don't have another computer, let me know.