Well...you can start by explaining...system symptoms which make you believe you have malware issues.
HJT logs are tools to be used in malware situations.
If you don't believe you have malware issues...HJT should not be your tool of choice. But you certainly need to provide more info on what the issues are (as you see them), system, etc.
The forum for malware logs: BC Virus, Trojan, Spyware, and Malware Removal Logs - http://www.bleepingcomputer.com/forums/forum22.html
If you intend to post a malware log, please read/follow the instructions (#7 thru #9) at Preparation Guide For Use Before Posting A Hijackthis Log - http://www.bleepingcomputer.com/forums/topic34773.html