I had the problem About:blank... smart search, my explorer changed everytime I opened it new and tried to download stuff onto my desktop. How I solved it...
1. Spysweeper from webroot (free download) blocked the attempted takeover everytime (it worked better guard than spyguard), so I could still search the net.
2. I tried Buster, spysweeper, spybot, ad adware, hijack, find and fix CWS shredder, stinger, trojan hunter, find n fix, spybot and others... They all found things (and cured past infections) but NONE cured this new About:blank smart search. then I found ANTIVIR version 6. It told me my MSXWORD.DLL was infected by PMS/TLBar.XMFi.
3. I used Regedit to search for "msxword" and I deleted everything that I found.
4. re ran antvir
5. re booted
and it was gone. after three months of trying.
I would like to thank everyone involved in developing all of the above software, everone who contributes to spyware info and donates time and money to help the average infected user like me. I never would have done it without you all. Thanks a million