Hi! I have XP sp3 installed twice on my PC from the same CD. I recently reinstalled on disc 1 owing to strange explorer behaviour which has now returned. It has never affected the installation on disc 2. The PC boots happily, startup objects load and run and applications can be run. However, I cannot access any drives via My Computer or Explorer for about 45 seconds. During that period I cannot close opened applications and they leave an ' image trail' behind them if I move them around the desktop. The CPU is not at 100% and Kaspersky did not find any virus, nor AVG any spyware. Then suddenly everything works fine, until the next re-start. This affects all users. It does not occur in Safe Mode. PC is 2yr old, P4 3.2GHz Northwood, 1Gb RAM. Runs like a dream, except as above. Anyone have any ideas? Thanks.

Solved by using the 'boot using last known good configuration' bootup option. How it cured it and what the cause was, I'll never know, but i don't care as it's now running perfectly again.