I've been using Ubuntu on my laptop for awhile now. Not quite used to it yet. I've got a Acer Aspire with an orig 4 gig mem/500 gig HDD. Running 12.04 presently 32 bit sys. I have the 13.04 upgrade disc and want to upgrade my memory to 8 Gig. Everytime I install the 8 gig memory, the system won't boot to either version. I downloaded the 64 bit version of both versions of Ubuntu but no results yet. Can anyone offer a suggestion here? I'm kinda lost.

Additional Information:
The memory was purchased through Acer/Kingston. Recommended for this computer. I watched the video on installing it, so I doubt it's installed wrong. (There's only one way of putting it in). I swapped Op Sys, from Ubuntu 12.04 to 13.04 to 13.10 and now to Xubuntu 13.10 64 bit version. I'm still not having any luck with this upgrade. Would it be necessary to upgrade the CPU? It's just a thought, I don't know what else could keep me from utilizing the new memory.

Additional Information: Called Kingston this afternoon, they are sending replacement lower density memory modules 2/4 gig - 8 gig. Tech service says I need to upgrade BIOS to utilize new memory install VIA Dos since it is no longer a windows system. I'm not sure how to go about that but it's a learning process I can live with. Thank you all for your help/support. I realize this isn't a Ubuntu problem but each new user of this op sys, seems to share simular problems and maybe someone can use this info to their advantage.