You first need to go to Add/Remove and uninstall PC Check-up. If you cannot find it there then go to C:\Program Files\PC Check-up\ and uninstall it from there.
Then run HiJackThis again and place checkmarks next to the following entries if they still exist;
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O2 - BHO: Thunder AtOnce - {01443AEC-0FD1-40fd-9C87-E93D1494C233} - C:\Program Files\Thunder Network\Thunder\ComDlls\TDAtOnce_Now.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\2.0.301.7164\swg.dll
O2 - BHO: Ask Toolbar BHO - {F0D4B231-DA4B-4daf-81E4-DFEE4931A4AA} - C:\Program Files\AskSBar\bar\1.bin\ASKSBAR.DLL
O3 - Toolbar: (no name) - {4E7BD74F-2B8D-469E-CCB0-B130EEDBE97C} - (no file)
O3 - Toolbar: Ask Toolbar - {F0D4B239-DA4B-4daf-81E4-DFEE4931A4AA} - C:\Program Files\AskSBar\bar\1.bin\ASKSBAR.DLL
O4 - HKLM\..\Run: [PC-Checkup] "C:\Program Files\PC Check-up\PCCheckUp.exe" -mini
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\1.2.1128.5462\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O4 - HKCU\..\Run: [updateMgr] "C:\Program Files\Adobe\Acrobat 7.0\Reader\AdobeUpdateManager.exe" AcRdB7_0_9 -reboot 1
Once you have those checkmarks placed then click the Fix Checked button. Exit HJT.
Reboot the computer and run one more HJT scan and post the log here.