XP crashes when playing games(Civilisation)

The failure is always IRQ Less Than. It only happens when playing games - memory check reports no problems. I have attached the last 2 minidumps. I have updated the obvious drivers I wonder if anyone can point at the problem.
Thanx John

Hello and welcome to Techspot.

Both minidumps crash at USBPORT.SYS and have a bugcheck of D1.

I cannot be sure from just 2 minidumps, but it may be a problem with one of your usb devices.

On the other hand it could be something else entirely.

0x000000D1: DRIVER_IRQL_NOT_LESS_OR_EQUAL

The system attempted to access pageable memory using a kernel process IRQL that was too high. The most typical cause is a bad device driver (one that uses improper addresses). It can also be caused by caused by faulty or mismatched RAM, or a damaged pagefile.

Go HERE and follow the instructions.

If that doesn`t help. Zip 5 or 6 of your latest minidumps together and attach them here.

Regards Howard :wave: :wave:

Further dumps

If I remember correctly the majority point at the USB port although not all of them. Here are a further 5. I have been running with verifier on which stops the dumps but the game crashes (can go for hours without a crash and sometimes it fails a second time within 10 minutes) with a send microsoft error information but this does not achieve anything. I don't usually have any USB devices active when I am playing.
Cheers John
P.S. I am physically handicapped and find it impossible to access boards etc. I rely on onsite maitenance agreements but it is not the sort of problem you can demonstrate to an engineer.