Windows recognises 8gb RAM but only 3.96gb usable

[DaCosta5396]

Windows recognises 8gb RAM but it bsays only 3.96gb usable, any ideas how to solve it?

 

[rolli59]

In this go to things to try and try them http://support.microsoft.com/kb/978610

 

[DaCosta5396]

Best answer selected by DaCosta5396.

 

[DaCosta5396]

Thanks for the help
Fixed it....tested both dimms on their own and then put them both in at the same time booted to bios noticed they were only running at 900mhz so i moved them up to 1333 and voila! 8gb ram
And i have no idea how