A number of months ago, I had what seemed to be a similar issue with my computer where Internet Explorer would slow to a crawl, hang and/or stall and CPU usage would jump to 100%. After following your suggestions, I posted a HijackThis log and was walked through steps to improve performance. I noticed a slight improvement. Since then, the problem has resurfaced and compounded.
I use Windows XP, have run Avira AntiVirus, SuperAntiSpyware and Ad Aware (which will freeze in about the same place during complete scans, but will work normally for smart scan. Incidentally, I had this same problem with Ad Aware the last time I sought your assistance and I was referred to Lavasoft's message board where I posted my concern. I never received a response) and nothing seems to work.
Can you please help? Thanks in advance.