I'm just wondering if you have the Bing Desktop installed which comes occasionally with Windows Updates.
You can check this by going Start - type windows update and press enter then click on Installed Updates and scroll through the list.
If you come across one for Bing Desktop, right click on it and select Uninstall - follow the prompts then let Windows do its thing.
After the computer has rebooted, go back into Windows Updates to check if any updates are being offered again, click where it may say one or more are Recommended/Important and if any are for Bing Desktop, right click on it and select Hide - OK.
Go Start - All Programs - Accessories - System Tools - Internet Explorer (No Add-ons)
IE will start, informing you that you are running IE without add-ons.
Click on the home page icon and see if you are getting the same problems and if so, go into Tools - Manage add-ons - check to see if there's anything for Bing and disable if any showing - OK and restart IE to effect.
IE will start as normal but if the problem persists, then you will need to start it again without add-ons.
If IE works okay without add-ons and you don't have an add-on for Bing, then uncheck all of the add-ons and restart IE.
You will then have to enable each add-on in turn and restart IE until the problem returns to find the problematic add-on.
Select Search Providers - click on the Search for more providers link bottom left and when the window opens click on Google - Add to Explorer and follow prompts.
You will need to restart IE for that to effect and then go back into Manage add-ons/Search Providers - set Google as the Default and Move up.
You can then disable Bing - click on the box to Prevent programs from making changes etc. - Close - then restart IE
MS has a fixit to make IE safe and stable and fix any troublesome add-ons so give it a try
http://support.microsoft.com/mats/ie_performance_and_safetyYou may have to restore back to earlier if you have the restore points to resolve the corrupted files that sfc /scannow found.
It's recommended to run sfc /scannow up to three times if it reports unable to repair all files.
The CBS log that sfc produces is usually quite large, but if you run a chkdsk /f and when it has completed go Start - type eventvwr and press enter.
Wait until it has read the logs then click on Windows Logs/Applications and look for a Winninit entry and click on it - then the chkdsk /f report will appear in the pane below.
If one isn't apparent then right click on Applications - click on Find then type chkdsk or winninit into the Find box - OK - close the box and then you can read what the chkdsk /f found and what it was unable to repair - also check to see if it reports any KBs in bad sectors.
While I have a solution that can fix corrupted files for Win 7 by booting up with a Win 7 install disk, I'm not sure if the same command works in Vista, but you would need a Vista install disk with SP2.
If chkdsk /f or sfc /scannow continues to report it is unable to repair all files, then I'll have to leave that for Shane to advise you as to a resolution.