Hello gryffud and Welcome to TSG! 
Download Ad-Aware SE from here:
http://www.download.com/3000-2144-10045910.html?part=69274&subj=dlpage&tag=button
Install and run Ad-Aware SE. On the bottom right corner of Ad-Aware you will see an option called "Check for updates now", click on that and choose "connect". Download the updates. Next click on "Scan now" on the left side of Ad-Aware. Make sure that "Search for negligible risk entries" is crossed out and not ticked. Choose "Perform full system scan" and click "Next". After Ad-Aware scans your computer, Ad-Aware may find some bad files on your computer so make sure you tick them all and choose "Next". It will ask if you want to remove those items so just continue. After removing the items close Ad-Aware.
Download Spybot S&D from here:
http://users.skynet.be/fa936042/spybotsd13.exe
Install and run Spybot S&D. Choose "Search for updates". Next choose "Download updates". After that, choose "Search and Destroy" and click on "Check for problems". If Spybot finds any nasties on your computer, make sure that they are ticked and choose "Fix selected problems".
Download SpywareBlaster from here:
http://www.majorgeeks.com/downloadget.php?id=2859&file=11&evp=61b0e8ad41924a03c37615f4682b4cef
Install and run SpywareBlaster. Click on "Updates" and then choose "Check for updates". Next choose "Protection" and at the top you will see different tabs which are Internet Explorer, Restricted sites and Mozilla/Firefox. Choose one of them at a time and at the bottom click "Protect Against Checked Items" (make sure that all of the items are checked). Tick the boxes above the items. Make sure you do this for all of the top tabs. Mozilla/Firefox you only need to do if you have the user profiles on your computer. You may now exit out of SpywareBlaster.
Download CWShredder from here:
http://cwshredder.net/bin/CWSInstall.exe
Install and run CWShredder. Click on "Check for Update" and download the latest updates. Next, click on "Fix". Exit out of CWShredder.
Restart your computer and post a fresh HijackThis log back on this thread.
Download Ad-Aware SE from here:
http://www.download.com/3000-2144-10045910.html?part=69274&subj=dlpage&tag=button
Install and run Ad-Aware SE. On the bottom right corner of Ad-Aware you will see an option called "Check for updates now", click on that and choose "connect". Download the updates. Next click on "Scan now" on the left side of Ad-Aware. Make sure that "Search for negligible risk entries" is crossed out and not ticked. Choose "Perform full system scan" and click "Next". After Ad-Aware scans your computer, Ad-Aware may find some bad files on your computer so make sure you tick them all and choose "Next". It will ask if you want to remove those items so just continue. After removing the items close Ad-Aware.
Download Spybot S&D from here:
http://users.skynet.be/fa936042/spybotsd13.exe
Install and run Spybot S&D. Choose "Search for updates". Next choose "Download updates". After that, choose "Search and Destroy" and click on "Check for problems". If Spybot finds any nasties on your computer, make sure that they are ticked and choose "Fix selected problems".
Download SpywareBlaster from here:
http://www.majorgeeks.com/downloadget.php?id=2859&file=11&evp=61b0e8ad41924a03c37615f4682b4cef
Install and run SpywareBlaster. Click on "Updates" and then choose "Check for updates". Next choose "Protection" and at the top you will see different tabs which are Internet Explorer, Restricted sites and Mozilla/Firefox. Choose one of them at a time and at the bottom click "Protect Against Checked Items" (make sure that all of the items are checked). Tick the boxes above the items. Make sure you do this for all of the top tabs. Mozilla/Firefox you only need to do if you have the user profiles on your computer. You may now exit out of SpywareBlaster.
Download CWShredder from here:
http://cwshredder.net/bin/CWSInstall.exe
Install and run CWShredder. Click on "Check for Update" and download the latest updates. Next, click on "Fix". Exit out of CWShredder.
Restart your computer and post a fresh HijackThis log back on this thread.