Here's the culprit in your particular case:
O2 - BHO: ohb - {98640C3B-0699-4D51-ADB4-A6FC48ACB966} - C:\WINDOWS\system32\nst1C.dll
1. Go to Start -> Programs -> Accessories -> Command Prompt; this will open a DOS box. Type the following command at the DOS prompt and then hit Enter:
regsvr32 /u C:\WINDOWS\system32\nst1C.dll
2. Run HijackThis again and have it fix:
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page =
O2 - BHO: ohb - {98640C3B-0699-4D51-ADB4-A6FC48ACB966} - C:\WINDOWS\system32\nst1C.dll
O16 - DPF: {DE910060-8EFB-44B9-B492-75180696643F} (iiittt Class) - http://www.hotsearchbar.com/toolbar30/hsrb.cab
3. Reboot into Safe Mode. You get to the Safe Mode boot menu option by hitting the F8 key just as your computer is starting up (before Windows starts).
- Open Windows Explorer, and in the Folder Options->View settings under the Tools menu, select "show hidden files and folders", and uncheck "Hide protected operating system files" and "Hide extentions for known file types".
- Locate and delete the following file:
C:\WINDOWS\system32\nst1C.dll
- For every user account listed under C:\Documents and Settings, delete the entire contents of the following folders (but not the folders themselves):
(Important: One of the normal steps in eliminating malicious programs is to entirely delete the contents of all Temp folders. Given that, if any data that you care about is living in those Temp folders, you need to move it to a safe location now, or it will be erased along with everything else!)
1. Cookies
2. Local Settings\Temp
3. Local Settings\History
4. Local Settings\Temporary Internet Files
- Delete the entire content of your C:\Windows\Temp folder.
- Delete the entire content of your C:\Windows\Prefetch folder.
Note- If you get any messages concerning the deletion of system files such as desktop.ini or index.dat, just choose to delete those files; they'll be automatically regenerated by Windows if needed. Windows will allow you to delete the versions of those files which exist in sub-folders within the main Temp/Temorary folders, but might not let you delete the versions of those files that exist in the main Temp folders themselves; this is normal and OK.
- Empty your Recycle Bin.
4. Reboot normally, run HijackThis again, and post the new log.