Unable to start programs after hibernate/shut down

Hi,
Frustrating problem - every time my computer goes into hibernation or suspends, when it reloads up, I can't start any program, just recieve the error message ' windows cannot access the specified device, path or file. You may not have the appropriate permissions to access the item'.

Can't find the answer anywhere - am running microsoft xp version 2002 on a sony vaio with intel t2400, 1.83Ghz, 512MB RAM. Have also got Zonealarm security suite running, but I think it was happening before I installed this.

Thanks for any help
Ben