Most of us choose to delete our browsing history every once in a while, via Internet Options. But at times, especially when the URL is a long one, you may find that you are unable to delete them from the browsing history, on your Windows 7 computer.
Cannot delete long URLs
This happens because Windows Search does not guarantee that URLs that are longer than 425 characters will be deleted.
To resolve this issue, Microsoft has released an update which you can download from KB2547666.
After you apply this update, your Windows 7 will index the file system. and you will be thereafter able to delete the long URLs again..
This is a one-time operation that may take some time, however.