I've disabled SearchHost.exe, because it sucks up 100Mb of RAM for no reason, every minute my box is running.
I think SearchProtocolHost.exe is a related process, so that's disabled on my machine, also.
Both are required for the start menu to work properly. Disabling them slows the menu down significantly. They're not optional services in Windows.
100mb of ram is nothing. Average low end PC's have 16GB and most midlevel to high end run 64gb. 100mb of ram is nothing.