Windows 7 - Mixing ram 1gb ddr2 667 and 2gb ddr2 800

Why is it that my cpu can only read 2gb?do i need to overclock/underclock the other ram?

Since you did provide computer specs, I assume 1GB is allocated to onboard video memory.

Hello retryme07 and welcome to Seven Forums.

This behavior is the expected result of certain hardware and software factors.

Various devices in a typical computer require memory-mapped access. This is known as memory-mapped I/O (MMIO). For the MMIO space to be available to 32-bit operating systems, the MMIO space must reside within the first 4 GB of address space.

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

The system memory that is reported in the System Information dialog box in Windows Vista is less than you expect if 4 GB of RAM is installed

In plain English, a portion of any installed RAM is set aside for other uses.

Mixing RAM of different speeds is not advisable and your current setup will run at the lower clock speed of 667 MHz.

You haven't posted your computer specs. Doing so will help us to help you.

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here check this.maybe it can help

I think Marsimar's comment has answered your query admirably.

Have you read the link he gave you?

problem solved.. thx alot guys