I've just upgraded my computer's memory but my computer is showing less RAM usable than what I've installed (i.e. 8GB installed, but only 3.5GB usable).

If you are using a 32bit operating system you can only address a maximum of 4GB of RAM(Random Access Memory) including but not limited to RAM on graphics cards and other devices, therefore you would require a 64bit operating system to recognise anything more than 4GB of RAM.

If this doesn’t solve the problem please contact our technical support department for further assistance.