I was just wondering what this program does and how it helps your computer and if its any good?

anyone? lol

Check the introduction section to the BC tutorial about HJT:

http://www.bleepingcomputer.com/forums/tut42.html

This tutorial is a great introduction to the application and its use. Often the correct use of the log depends on a level of experience and expertise not normally found in most computer users; consequently, BC has a trained team of volunteers that will review HJT logs and help members clean their hard drive of malware.

Regards,
John

In addition to what jgweed has suggested, could i just add if you feel the need to submit a HighJackThis log, you might like to read this

How to submit a HJT log
Could i also add, if you are in any doubt as to what to delete using this program...please don't delete anything until you have had your log read by a professional. Used incorrectly, this program can do a lot of damage to your computer.