Unzip HJT into it's own permanent folder before doing anything in order for it to create backups. (Not a temporary folder or the desktop & not directly on your hard drive). Click My Computer, then C:\
In the menu bar, File->New->Folder.
That will create a folder named New Folder, which you can rename to "HJT" or "HijackThis". Now you have C:\HJT\ folder. Put your HijackThis.exe there, and double click to run it.
Close all (browser) windows & rescan with hijackthis. When the scan is finished place a check in the box to the left of the following entries & click 'fix checked' :
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://red.clientapps.yahoo.com/cus...//www.yahoo.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://red.clientapps.yahoo.com/cus...//www.yahoo.com
R3 - Default URLSearchHook is missing
N1 - Netscape 4: user_pref("browser.startup.homepage", "http://www.bbnow.net/"); (C:\Program Files\PBI\Users\User1\prefs.js)
O2 - BHO: (no name) - {179B07CB-ECAA-E0B9-C1DF-7E77937E9CCF} - C:\windows\system\zavgxrld.dll
O2 - BHO: (no name) - {4FD4DD82-61CD-CACD-EA50-9B8B6D8AAEDA} - C:\windows\system\wmpnjmuy.dll
O3 - Toolbar: (no name) - {014DA6C9-189F-421a-88CD-07CFE51CFF10} - (no file)
O4 - HKCU\..\Run: [] c:\WINDOWS\System\
O19 - User stylesheet: (file missing)