I can confirm that on my PC Google Desktop Search is extremely buggy in insidous ways, and hurts the operation of other Windows programs. On my computer* I can run WinXP for months without rebooting until recently. I run dozens of utilities and programs and 50 or 60 browser windows simultaneously. Many mysterious problems have been happening for last month where programs won't start, or the Windows Start menu will loose all of it's menu items forcing me to reboot to restore it, or right mouse clicks stop responding forcing me to reboot several times a day. I systematically removed the various utilities I use (Clipmate, UltraMon, DesktopSideBar, etc.) with no effect. The minute that I removed Google Desktop Search the problems vanished.
* 2.6 ghz Pentium4 dektop, 160 and 250 gig disk, 1gig of RAM with 3 monitors.
I attacked Hotmail @ in a [MicrosoftCommunity] message because Hotmail wouldn't let me send an 11mb attachment in a non-free account I paid money for and my GMail free account would send the same attachment. Now Gmail has broke their unlimited attachment size promise to me.