Just installed 4GB of RAM but only 3.25 available?

[LFCJohnSmith]

I have just put 4GB of RAM in my pc but although my PC has detected 4GB it is saying I can only use 3.25GB of RAM for some reason, why is this? I have Windows 7 64bit installed on my PC so why wont it use the full 4GB?

 

[Yami]

You're positive it's 64-bit?

Does all 4GB show in BIOS?

In Msconfig/Boot/Advanced Options, do you have the Maximum Memory box ticked?

 

[LFCJohnSmith]

You're positive it's 64-bit?

Does all 4GB show in BIOS?

In Msconfig/Boot/Advanced Options, do you have the Maximum Memory box ticked?

It is defo a 64 Bit version of Windows 7, and I have just gone into msconfig and selected that check box, now I am going to reboot my pc and hopefully come back with 4GB of RAM. I will update shortly.

 

[LFCJohnSmith]

I have just done that but it isn't working. What is it I have to do exactly because when I check the box and then reboot my pc and then if I go back to it, it just goes back to normal.

 

[Slaymate]

My system is showing that box unchecked, It shouldn't matter. Does your PC have built-in video?

 

[LFCJohnSmith]

yes it has an on board graphics chip but I use a graphics card.

 

[Slaymate]

See if this makes a difference. Go into the bios, even though your using a separate card, and set the amount of memory reserved for the on-board video to it's minimun setting. You may have to enable the on-board video to adjust this, just disable it again after you change the setting.

 

[LFCJohnSmith]

will do

 

[LFCJohnSmith]

Think the problem is the chipset on the mobo. I have a 945 chipset and from what I can gather the chipset can only recognise the same amount of RAM as a 32 bit OS. It's either that or the devices such as graphics card and other devices are using the RAM as cachable memory.

If anyone knows anything else then please do tell.

 

[Slaymate]

I never knew that, but the 945 chipset can only address 4GB of memory.

Intel 945G Express Chipset - Overview