How do I know what model my compaq CQ42 is?

[lohroc]

I want to upgrade a compaq CQ42 processor. I downloaded the maintenance guide and it has the available processors on page 94 but between parenthesis "for models 1.0 and 1.1 only" for example. I need to know what model it is to buy a better processor for it.

It has a sticker behind the battery with

Model:CQ42-212BR

Product:XA769LA#AC4

[Huffer]

Its very hard to tell you have to use some logic as to what is installed on your laptop and the hardware that is compatible with the various model types. Your specs say you have a Pentium 2.3 ghz processor and the only thing close is the 

Intel Pentium P6300 - 2.26-GHz 3M (for model 1.3 only) 635500-001

So I would do a check on the processor and see if it is a P6300 and if so yours must be model 1.3 and you can install up to an i5-560M. I would also do a Sysoft Sandra analysis of all the hardware to see what chips are used. The CQ42 spans the Core 2 Duo and first gen Intel Core (i3, i5, etc) world and you want to be sure yours is not one of the GL40 chipset models that will only take the older processors.  

[lohroc]

It has a Pentium(R) Dual-Core CPU T4500 2.30GHz

How do I check that on linux?

[Huffer]

Which Linux distro? There is usually a system information applet which will tell you a great deal about the hardware. 

[lohroc]

It has Pentium(R) Dual-Core CPU T4500 2.30GHz what upgrade options are available for me?

[Huffer]

That means you have the GL40 chipset which will not even support a Core 2 Duo...The T4500 is as good as it gets I'm sorry to say. 

[lohroc]

What do you mean by 'chipset' the ghraphics processing unit?

The motherboard is

Base Board Information
    Manufacturer: Hewlett-Packard
    Product Name: 1484
    Version: 77.39

[Huffer]

It is going to be real hard to communicate about this if you do not know what a chipset is, but I am referring to the main controller chip on the motherboard, sometimes called the I/O chip. In your case it is the Intel GL40. It is a budget component and only supports Celeron and Pentium Dual processors, not the more full-featured Core 2 Duos:

http://www.cpu-upgrade.com/mb-Intel_(chipsets)/GL40_Express.html