Basically it gives you a rundown of everything that's currently screwing with your computer or calling itself up on startup(If I'm remembering correctly.), even stuff your task manager and Install/Remove programs won't show.

It's a bit technical to use since it also shows perfectly legal stuff, like your AV software, your firewall, basic system files, etc.

However, if you do it, print out the log and share it with someone who knows what they're doing, they can almost always tell you if you've got malicious software and what you should annihilate.

To expand on what Purple said, HJT looks through the registry for suspicious behaviors. Keys, browser helpers, and other things. It brings those to your attention, and you can then decide what to do with them. For example, since I've got Acrobat installed, the Acrobat browser helper is okay.

It differs from other spyware tools in that instead of looking for bad *things*, it looks for bad behavior. So it may bring up innocent things.

The good news is that you can train it to ignore those things in the future.

The bad news... prepare to spend a lot of time googling for executables to see what they do. I'll give you one head start... I tend to trust liutilities.com as a reference source, along with a couple of others.

I tend to have a very no-nonsense policy with HJT. If I know it's something I've installed or it's an important Windows file, it gets to go on the Ignore list, otherwise I just wipe it on principle. I don't care what it does, if it's on there without my permission, it goes.

Your best bet is to use HT then go to their forums and ask if someone can look at your log. Instead of spending forever they can tell you what does and doesn't belong there. I've done it before.