Installation only recognizes 3 GB of memory after RAM upgrade [duplicate]

Possible Duplicate:
Why does Ubuntu only show 3GB of RAM?

I recently upgraded my system from 2 to 4 GB of memory. When I booted into Ubuntu, it's only recognizing 3 GB.

I followed some instructions on adding the PAE; now when I boot up my kernel has switched from generic to PAE but I'm still only showing 3 GB. How do I get it to read all 4 GB?

I went to the Software Center and found the PAE, then when I clicked "More info" it shows a few more packages with it but they aren't checked. Should I check them to be added also? Will this make Ubuntu recognize my 4 GB?

Solution 1:

To start with, what version of Ubuntu have you installed? 32bits or 64bits? If I'm correct 32bits systems won't be able to use more than 3Gb of memory, try with the 64bits version.