Ad d memory to an HPpavilion ze 4900

spy sweeper has knowen compatiblity issues

From the research that I've done of the ze4900 the maximum is 1GB but I also read that some can go up to 2GB, I need the HP part number of your laptop to know for sure, it's a 7 or 8 digit string that starts with a P then another letter, 3 numbers, then two more letters. You can find it on a label under the system with the serial number. Thanks.

The notebook has 2 slots that hold 2 RAM modules. At least 1 slot contains a RAM module installed at the factory. You can use both slots to expand your RAM.
I dont see any reason you couldnt use 2 1 gig modules.