The properties Description field says 4.4.3.3.  I don't know what shell extensions are (but they sound very useful) so I expect that I don't have any running.  I see nothing in any of the event logs near these times but I did not attend closely.  Should I look to see if the Task Manager sees PM after it appears to close?  Does PM have more than one process?  I am running WinXP Pro 2002, SP2, no build information on AMD 64X2 Dual Core 4400+ 2.21 GHz 3.37 GB RAM a TB of disk storage in two RAID arrays. You can email me if you'd like me to attempt any diagnostic procedures.  I not recall having this issue on my "work" machine at school ... might it be SMP related? I'll check back here tonight or tomorrow, too.