Hi RJ,
I'm not one of the virus experts here, but your log says your system captured a trojan backdoor, probably W32.RBot.HA or an old one that uses the filename "regscan.exe":
Process:
C:\WINDOWS\system32\regscan.exe
Registry key:
O4 - HKCU\..\Run: [Regscan] C:\WINDOWS\system32\regscan.exe
It's described here:
http://www.sophos.com/security/analyses/w32rbotha.html
You can follow the removal instructions there.
This entry is also considered nasty, but rather harmless: (Spyware)
O4 - Startup: PowerReg Scheduler V3.exe
It's described here:
http://www3.ca.com/securityadvisor/pest/pest.aspx?id=453078189
But I wonder why your antivirus software doesn't find anything? Did you update it before running it? Did you run it in safe mode? Maybe you try this one:
http://esupport.trendmicro.com/support/viewxml.do?ContentID=en-125991
and run an updated Spybot S+D in safe mode, let it remove everything it finds.
Disable system restore to remove all restore points, since the trojan is most likely buried there, too.
I'm not one of the malware removal experts here and just wanted to help out, so I can't give you real instructions on that, sorry.