How to remove trojan horse PSW.generic8

Fiona, In order to analyze it please provide AVG with GMER (http://kb.avg.com/articles/en_US/How_to/GMER-Scan-Result/) and AVG scan result export (http://kb.avg.com/articles/en_US/How_to/AVG-scan-result-export/).
AVG Guru

Hey everyone,

My laptop today was incredibly laggy, slow, non-responsive. AVG has detected a trojan (trojan horse PSW.generic8) but wont remove it. I get the error "cannot be removed. The data is invalid".

Laptop info:
Windows 7 Home Premium
Service Pack 1
(sorry if more info required, I'm not clued up on this)

Can anyone help me to figure out how to remove this please? The CPU is fluctuating around 99%

Fiona, In order to analyze it please provide AVG with GMER (http://kb.avg.com/articles/en_US/How_to/GMER-Scan-Result/) and AVG scan result export (http://kb.avg.com/articles/en_US/How_to/AVG-scan-result-export/).
AVG Guru