In search for a solution to the problem, I found that using ewido's online scanner can solve your problem.
http://www.ewido.net/en/onlinescan/
The scan hasn't actually finished yet so although I don't know if it'll remove it and it may be a bit unresponsible of me, I suspect I'm going to have to reboot for this thing and by the time I get back online, I'll have forgotten about it.
I have done some looking around and working and found out that it was WINUPDATERS.EXE that was/is in my C:\WINDOWS\SYSTEM32 folder which was causing the Task Manager among other things to close immediately after closing. I found out because, using cmd, tasklist and taskkill, I stopped it and was able to open the above.
I should probably remove the trojan myself now that I have the chance but I'd like to make sure ewido works.