Ok the link below is the specs specifically for my Compaq computer. If you read where "Max. Memory Allowed" it shows 1Gb (2 X 512Mb)
http://h10025.www1.hp.com/ewfrf/wc/genericDocument?docname=c00280659&cc=us&dlc=en&lc=en&jumpid=reg_R1002_USEN
Ok now I looked up the maximum allowed for the motherboard itself and it says 2Gb Maximum Allowed (2 X 1Gb)
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00069442&lc=en&cc=us&dlc=&product=436281
Which one do I go with? I already have 1Gb installed with Vista. I want to go up to 2Gb but I don't really want to burn out the motherboard 
help?
Ok I checked the Crucial site and I got 2048 "maximum" Is that the actual max the motherboard will hold? Also I upgraded from XP Home to Windows Vista.
"Support up to maximum 2 GB memory (PC manufacturer's maximum memory may differ)"
Notate the (PC manufacturers . . . . . )
That is NOT a good Vista machine.
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