Perhaps a visit here will get you going in the right direction.
Removing adware & spyware
How to beat your advertising popups & other browser nasties
FAQ608-3482
Removing adware & spyware
Before Posting a Hi-jack log file - Best Practices
FAQ608-4650
Make sure your options in IE/ Tools/ Internet Options/ Advanced are correct.
Uncheck the boxes for "Install on Demand" for IE and Other programs (two boxes).
Try running temporarily with the third box "Enable Third Party Browser Extensions" unchecked and see how this goes.
"This specifies that you want to disable features you installed for use with Internet Explorer that may have been created by companies other than Microsoft.
If you encounter problems with Internet Explorer that you cannot resolve, you can use this option to help determine if third-party features are causing the problems without uninstalling the feature. You must restart Internet Explorer after turning this option on or off."
If that stops your errors, you will know where the trouble is.
This article and the program BHOcop might be useful to you.