Lately, when I boot my PC I get the following error message: "Explorer caused a GPF in module User.exe at 0004:00001fae". At this point the PC is frozen and the only way to get out of it is to shut the power off. Sometimes it won't even shut off when I hit the power button and I have to shut off the power switch at the surge protector. When this happens I have to boot a couple of times before I get a "good" boot. Safe booting sometimes helps. Any Ideas/Suggestions?

BTW I do clean installs periodically and this is happening after a clean install. I have not added any "new" programs or hardware.