Vista slow boot and operation. Malware problem?

My system is a 3.3 ghz celeron D with 1.5 gb ram, running vista home premium. High-speed iinternet (10mb/sec). Boot times are about 8 minutes. Connecting to new web page takes several minutes, e-mail is very slow. I assume the problem is malware but don't know how I got it or what it is. I downloaded Process Monitor and ran it during boot - it recorded about 300,000 operations but I couldn't see anything obviously wrong. Help!!!

A hijackthis log is as follows:

 

Please do not post inline logs, they need to be attached as a text file.

Also, please run through this before we continue

http://forums.majorgeeks.com/showthread.php?t=35407

 

I have completed all suggested actiions in the Read & Run etc file. Logs are attached. i should note that I have had numerous other problems such as program failures ( outlook, IE, and other) and my quicken files have been deleted mysteriously.

 

I have no idea why winword was open. I didn't use it. Outlook I normally use. CounterSpy was not run since it it not suggested for Vista in your procedure. I assumed from that that it did not run under Vista. After your response, I did run it but failed to capture the log. Four problems were noted, one of which was medium-high risk, one was ignored. The top 3 were quarentined.

To improve boot times I shut down everything (via msconfig) that I thought I could get away with keeping most microsoft services and the CA security. Boot time to Sidebar is about 4 minutes with cpu utilization remaining near 100% for a additional 4 minutes. Loading IE and opening a web page is now about 30 sec. Outlook now loads more quickly but a lot of HTML text is present.

My computer remains somewhat unstable. Certain processes regularly fail, e.g., windows photo screen saver, others ocasionally, e.g., outlook & IE. I have had my Quicken data deleted several times. Perhaps I just have a corrupted Vista installation and its time for a clean reinstallation or to backtrack to XP Pro. Any advice?