Are they advertisements, redirects, etc.? What scanners have you run?

Try Super AntiSpyware. If you do not routinely clean cookies and temporary internet files this could take a while. Some users have reported scans taking over 24 hours.

If you use CCleaner first, that will clean/eliminate cookies and temp files, thus making the SAS scan shorter.

Download and scan each user profile with CCleaner:
http://www.ccleaner.com/download/builds
** Select to download the SLIM version.

**Because CCleaner removes everything in temp folders, if you have anything in a temp folder, back it up or move it to a permanent folder prior to running CCleaner.

1. Before first use, select Options > Advanced and UNCHECK
" Only delete files in Windows Temp folder older than 48 hours"
2. Then select the items you wish to clean up.
In the Windows Tab:
• Clean all entries in the "Internet Explorer" section.
• Clean all the entries in the "Windows Explorer" section.
• Clean all entries in the "System" section.
• Clean all entries in the "Advanced" section.
• Clean any others that you choose.
In the Applications Tab:
• Clean all in the Firefox/Mozilla section if you use it.
• Clean all in the Opera section if you use it.
• Clean Sun Java in the Internet Section.
• Clean any others that you choose.
3. Click the " Run Cleaner" button.
4. A pop up box will appear advising this process will permanently delete files from your system.
5. Click " OK" and it will scan and clean your system.
6. Click " exit" when done.
REBOOT.

Download and scan with SUPERAntiSpyware Free for Home Users

• Double-click SUPERAntiSpyware.exe and use the default settings for installation.
• An icon will be created on your desktop. Double-click that icon to launch the program.
• If asked to update the program definitions, click "Yes". If not, update the definitions before scanning by selecting "Check for Updates". (If you encounter any problems while downloading the updates, manually download and unzip them from here.)
• Under "Configuration and Preferences", click the Preferences button.
• Click the Scanning Control tab.
• Under Scanner Options make sure the following are checked (leave all others unchecked):
  • Close browsers before scanning.
  • Scan for tracking cookies.
  • Terminate memory threats before quarantining.
• Click the "Close" button to leave the control center screen.
• Back on the main screen, under "Scan for Harmful Software" click Scan your computer.
• On the left, make sure you check C:\Fixed Drive.
• On the right, under "Complete Scan", choose Perform Complete Scan.
• Click "Next" to start the scan. Please be patient while it scans your computer.
• After the scan is complete, a Scan Summary box will appear with potentially harmful items that were detected. Click "OK".
• Make sure everything has a checkmark next to it and click "Next".
• A notification will appear that "Quarantine and Removal is Complete". Click "OK" and then click the "Finish" button to return to the main menu.
• If asked if you want to reboot, click "Yes".
  
  If that does not help, post a HijackThis log on the Hijackthis board. Be sure to read the "HOW TO..." instructions at the top of that board.