I'm using Firefox 12.0 Ă, but this problem may also occur with IE (according to a Mozilla Support thread, referred to below).
Out of interest, I downloaded and installed Google Books Downloader, having seen a reference to it in a blog post (Codeplex daily summary - http://www.codeplex.com/) in my feed aggregator.
The download site is/was: https://googlebookdownloa...x.com/releases/view/84266
The proggie did what it claimed to do - copied previews of books to .PDF - which unfortunately wasn't of much use as you are still frustrated by Google's removing pages from all previews.
Then I noticed that my home page and also my default Google search page had been hijacked by a search page which was imitating Google, with a pretty seascape background (see copy in spoiler):
The ruddy thing wouldn't go away.
So, I de-installed Google Books Downloader and googled the problem, coming up with a useful Mozilla Support thread at https://support.mozilla.org/en-US/questions/850780
The hijack is persistent and comes from the website 'arccosine.com' and wants you to "sign up" for something.
I did a 'Whois' on arccosine.com, and it is hosted in the Russian Federation. (That figures.)
I deleted all references to "arccosine" (i.e., 2x "C"s) and "arcosine" in history, just in case.
I checked in the 'about:config' entry for 'keyword.URL' and reset that back to "Default" - it had been set to 'arccosine.com,q=' by the hijack proggie Google Books Downloader (in the discussion thread someone writes that if you examine the proggie's code, you can see where it does that).
Hope this helps someone to avoid the thing.