[damien c]

i only mentioned it because and i know what people will say that acer is not hp but rather than you finding out, later and having to struggle with them about it hp told me that because a customer had installed a different os that caused the hardware failure stupid i know but that's what they said.

i didn't want you to be surprised if they said the same to you however i do feel that this is a software issue, rather than hardware due to your bios and cpu-z still seeing the 3gb.
i would suggest if possible a restore back to factory or a fresh install, of windows and see if it recognises the full 3gb if it doesn't then it's hardware imho.