on my compaq presario sr2011wm, the compaq site says that it supports up to 2gb of RAM max but it has ATI Radeon XPress 200 chipset in it that from what i've read at several sites can support anywhere from 4gb to 8gb on the intel platform, which is what mine has been fitted to. i'm currently maxed out at compaq's max, but i'm curious if anyone knows for sure if i can go up to at least 4gb?? this would be great if so...
Possibly when the machine was built, that was the max based on what chips were available and they haven't updated the information. If you have or can borrow larger capacity chips to test, you might be pleasantly surprised. I have had a few machines in the past that I upgraded to 2x or 4x the documented max and they worked just fine.
It all depends on the bios, a bios update if available might help you may be limited by the slots available and the size of the modules (2x2gb or 2x4gb etc). Also, if all the RAM is available from the RAM slot, you simply need to replace the RAM thats there with compatible modules. If the laptop has RAM modules elsewhere on the board, you may need to dismantle more of the laptop to remove the current memory. Some laptops have the RAM slot in addition to RAM that isn't accessible via the slot.