On Windows XP, some drivers, especially video adapter drivers with onboard RAM, cannot run with the /3GB parameter because they require more address space than the 1GB kernel address space permits.
We advise users that have added the /3GB switch in order to maximize their 'user-mode virtual address space' to 3GB from 2GB, to remove this switch.
It can cause your system to crash and may contribute to other issues. Please be sure to delete this switch from your boot entries: boot.ini and any other places where you may have this switch activated.
To find out more information about this switch, please visit the following link: