Remove the following entries and restart your computer
 
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = TOOLBAR - Comcast.net
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = Learn about Dell's notebooks, desktops, monitors, printers plus computer electronics & accessories.
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = TOOLBAR - Comcast.net 
R3 - URLSearchHook: (no name) - {0579B4B6-0293-4d73-B02D-5EBB0BA0F0A2} - C:\Program Files\AskSBar\SrchAstt\1.bin\A2SRCHAS.DLL 
O4 - HKLM\..\Run: [Host Process] C:\WINDOWS\Fonts\svchost.exe 
O4 - HKLM\..\Run: [f8393591] rundll32.exe "C:\WINDOWS\system32\liudqnog.dll",b 
O8 - Extra context menu item: &Search -  
http://km ..... 
O18 - Filter: text/html - {2AB289AE-4B90-4281-B2AE-1F4BB034B647} - (no file)