In preparation to rebuild my Windows Search Index, I installed the Adobe PDF iFilter for 64-bit on my system (Vista Business 64). When I finally rebuilt the index, I wasn't too surprised by what I saw happen, namely, the SearchFilter.exe process would kick in whenever I wasn't using the system and just eat RAM. One time I turned it on and it had allocated over 4,000 MB (and my system only has 4,030 MB available) so of course it was forcing all the other processes to hard fault (ie. everything was moving like molasses--for example, it took 20 minutes to put the thing to sleep). But I just let it do it's work, figuring that perhaps this was to be expected relative to the small library of PDF's that I've accumulated on my computer, ranging from LaTeX generated text files, to containers for hi-res scans. So, after a day and a half of basically not using my laptop, everything finally calmed down and I enjoyed the benefits of searching the content of my library from the Windows Start menu--for a short while.
However, to my dismay I've encountered the problem that this freezing of my computer would now occur after everytime I download a new PDF (in this particular case they were Google Books scans) and then left the computer to idle. Again, the SearchFilter.exe would allocate all of my RAM for itself and just push everything else onto the Virtual RAM, which means the SLOWEST possibly fetching you can get. I had to uninstall as this was making my computer unusable for 15-30 minutes after each idle. Everything is back in working order without the iFilter, but I would like to know if anyone has reported such problems on x64 systems. Obviously, I will also report the problem to Microsoft, since the search engine should certainly have the precaution to handle such memory problems. However, it is a problem that is created by the Adobe PDF iFilter interacting with the Windows Search engine.