To fix the "New Tab" issue in which your ICQ installation replaced the normal Internet Explorer "New Tab" with an ICQ Search Page New Tab:

Click Start
Click "Run"
Type:  regedit (in the Run Dialog Box)
Navigate to the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\AboutURLs

Right Click on "Tabs" (in the right column)
Left Click "Modify" on the Right Click Menu.
In the "Edit String" Window replace the contents of  "Value data" Dialog Box with:

res://ieframe.dll/tabswelcome.htm

Close the Registry Editor and restart Internet Explorer. Enjoy!

This will restore the original Internet Explorer "New Tab", and get rid of the ICQ Search "New Tab" Page in Internet Explorer.
Doing this requires editing the registry on your computer.
If you are not comfortable doing this you may want to live with your ICQ Search "New Tab"
Warning! - You edit your computers registry at your own risk, we will not be responsible for any improper registry editing you perform!!!