My work PC is a Pentium 3 GHz with 3Gb of memory, running Windows 2000 with Service Pack 4. Sometimes when I navigate folders or do a Windows task like opening "My Computer", Windows will stall for many seconds (like 15 - 30) and lock up the desktop. If I have task manager running it doesn't show any unusual CPU activity. This seems to happen randomly but often enough to get very annoying. The IT tech here couldn't find any problems. Changing network connections did not fix it, and no one else on the same network is having any problems. Can anyone suggest some typical causes of this problem?