Flash Drives not being recognized on laptop

HP Pavilion Entertainment PC, Windows XP, Service pack 3, all ms updates are installed.

no matter what Flash drive is plugged into the laptop, the laptop does not recognize it. you can plug the flash drives into any other pc/laptop and it is recognized.

Malwarebytes, Spybot Search and Destroy, Ad-Aware, Glary Utilites and McAfee Anti-Virus software have been runned on the laptop and it is clean, finally – yes there were some issues all but this issue has been cleared up and all the programs come up empty when it comes to any spyware/malware/adware/viruses.

What else can be the cause as to why the Flash drive is not recognized?

thanks,