Yeah like Johnb35 said.
For one, definitely read all of the article from BleepingComputer he posted the link to. Although there are HJT analyzers out there, don't put too much faith in them. The analyzers can catch things like virus entries and some other disabled entries. But they can also miss showing/marking items that aren't malicious, but are instead just bloating your computers running ability.
That is when you need to have a firm understanding of processes and how HJT works. This is so that you can read a HJT log and see what is needed, unneeded, unnecessary, foist-ware, malicious, clutter, illegal, etc....
I think its fun and interesting to work through the HJT, Malwarebytes, Combofix, logs to correct a problem.