Unfortunately, you DO have a virus. Apparent in these HJT entries:
O4 - HKLM\..\Run: [exp.exe] C:\WINDOWS\SYSTEM\exp.exe
O4 - HKLM\..\Run: [t74P3qh] LFELTC1.EXE
O4 - HKLM\..\Run: [AutoUpdater] "c:\Program Files\AutoUpdate\AutoUpdate.exe"
O4 - HKLM\..\RunOnce: [Registering hhctrl.ocx..] C:\WINDOWS\SYSTEM\regsvr32 /s hhctrl.ocx
O4 - HKLM\..\RunOnce: [Registering itircl.dll..] C:\WINDOWS\SYSTEM\regsvr32 /s itircl.dll
O4 - HKLM\..\RunOnce: [Registering itss.dll..] C:\WINDOWS\SYSTEM\regsvr32 /s itss.dll
O4 - HKCU\..\Run: [cwvFRkN3l] LFBCONFG.EXE
O9 - Extra button: WeatherBug - {AF6CABAB-61F9-4f12-A198-B7D41EF1CB52} - C:\Program Files\AWS\WeatherBug\Weather.exe (file missing) (HKCU)
You can remove those, but write down the files names because they need deleted. You can also remove any "poker" entires if you don't play. And most people around here hate Weatherbug as well, so you could remove that. Or uninstall from add/remove programs in Control Panel.
You need to do a virus scan, and to do that you have to be online. One of the favorites here is "housecall.trendmicro.com". It's a free scan. So IF you can get there and IF your PC stays alive long enough to download the control to run it, it just may clean you up.
Otherwise, clean up HJT and post another log.
Do you have Ad-aware and Spybot? If you can muster the stregth for the downloads, those are two free programs to get rid of spyware, i.e. popup problems. And many many other crapwares hanging around.
If Yahoo toolbar doesn't work, uninstall it as well from add/remove. And remove any references to it with HJT.
Download, yet again, a new and worlds better browser called Firefox from
www.mozilla.org. It automatically blocks popups without needing a resource hungry, 3rd party tool. Use it instead of IE. Except for housecall, which you will need IE to use.
Lastly, if you MUST have a popup-blocking toolbar, use google toolbar instead of yahoo.
Good luck