Unzip HJT into it's own permanent folder before doing anything in order for it to create backups. (Not a temporary folder or directly on the desktop & not directly on your hard drive). 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 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = res://C:\WINDOWS\plyux.dll/sp.html#37049
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = res://plyux.dll/index.html#37049
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = res://plyux.dll/index.html#37049
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = res://C:\WINDOWS\plyux.dll/sp.html#37049
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = res://plyux.dll/index.html#37049
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = res://C:\WINDOWS\plyux.dll/sp.html#37049
O2 - BHO: (no name) - {C00B7C3E-8355-5A94-2DCD-3B905BD5E422} - C:\WINDOWS\system32\winss.dll
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O4 - HKLM\..\Run: [sdkbq32.exe] C:\WINDOWS\system32\sdkbq32.exe
O4 - HKLM\..\RunOnce: [msmu.exe] C:\WINDOWS\msmu.exe
Reboot into safe mode following the instructions here & navigate to & delete the following if found:
C:\WINDOWS\system32\sdkbq32.exe< file
C:\WINDOWS\msmu.exe< file
Reboot normally after doing the above then post a fresh log plz.