Boot loop, URL redirects and I've tried for a week to do fix this on my own - fail.

Hello - I'm reaching out for your help. I've read a plethora of info, many similar issues out there, though nothing exact which is why I'm requesting attention and assistance. Thank you in advance

Problem: Before I did some cleanup of my own, HJT wasn't accessing the hosts file. Fixed that. Ran checkdisk - problems and reverted to a restore point. Yet there are still URL redirects, possible hijack of userinit.exe, programs running silent in background that wait to close when I log off, boot loops (there's a system password set in Toshiba Assist and it won't let me change it), I've set Chrome as my default browser yet IE opens. I'm using a 13 Jan 2011 hosts file from http://www.mvps.org/winhelp2002/ - I was using Webroot for a year and now using Avast! paid edition. Noticed that the past few days Microsoft Single Image installer loads each time I open a new browser window (not a tab) and a huge concern for data theft, keylogging etc.

I've downloaded all the tools you've recommended and I'm ready to go when someone has time to help.

Thanks so much ~

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Professional, Service Pack 1, 64 bit
Processor: Intel(R) Core(TM) i3 CPU M 330 @ 2.13GHz, Intel64 Family 6 Model 37 Stepping 2
Processor Count: 4
RAM: 3958 Mb
Graphics Card: NVIDIA GeForce 310M, 512 Mb
Hard Drives: C: Total - 464783 MB, Free - 359201 MB;
Motherboard: TOSHIBA, Portable PC
Antivirus: Webroot SecureAnywhere, Disabled (not true, the uninstall .exe was missing so I edited the registry and deleted what I could find referencing it yet obviously a key still lingers) I'm using Avast! paid edition