AVG identified hijackthis.exe as a trojan!!! And i let it clean! I got my hijack from trend website, windows vista version.
Why avg did that?

Many detection apps function in the same way-- as those they're trying to remove. Then another app ID's it as malware-- You need not be concerned.
AVG is responding to the way HJT would work-- to do their jobs AV programs err on the very safe side.
This is why they have "ignore lists" in AV apps-- so you can customize your protection to your particular setup.

Yup, it's pretty normal that HJT often gets falsly flagged as malware, but as Ih8bills said, nothing to worry about.

Thank you ih8bills and joe5, now i'll have to undo what AVG did and "rescue" HJT from "prison"...

Hehe, thread marked as Resolved. If you require more assitance please feel free to post