I am not sure why you say that you need "at least 800Mhz," but I can say fairly confidently that you will not notice the difference between 766 and 800. I suspect that some program you intend to use suggests the minimum of 800; it will probably run at 766, too, but at either of these speeds it is likely to be sluggish. If my supposition is correct, then, perhaps, you should try to run your stuff on your current system and see how it does. (If you have licensing costs involved, this may not be a desirable thing to do.) As you may have surmised, it may be quite difficult for you to upgrade your current system. When I upgrade, I almost always buy matching motherboard, processor, and memory at the same time. Also, one of the problems with a proprietary system like Compaq is that they often require (expensive) proprietary motherboards, and (inexpensive) generic motherboards will not fit in the custom Compaq case. The motherboard is the main board (usually green) that fits inside your computer and everything else plugs into it one way or another. The processor (cpu) is the thing that the 766 refers to and plugs into the motherboard. ("Intel Inside") What you would like to do is just purchase a new, faster processor, but that may not be possible, as others have pointed out. (It is like fitting a Corvette V8 into a Vega. I know a guy who did it, but he spent a lot of time and money to do it!) This is why I go back to my main point to try out your present computer with the software that you need to use for work. It may work more or less OK. Meanwhile, you can save up for a more substantial upgrade, which will likely involve a new case, motherboard, processor, memory, and operating system. If money is a big problem, you can go with a package. (Many of us like to dicker around with computers and customize them, but that can get expensive.) You might mention how you are using your computer at work, that is, what software package(s). Some programs need fast memory and fast hard drives to work at their best, and upgrading the processor will still leave other bottlenecks. If you have specific software that you intend to run, somebody here might give you an idea of how it will - or will not - run on your current computer. HTH Dean Kukral ----- Original Message ----- From: carmen strickland Sent: Sunday, November 27, 2005 9:30 AM Subject: [PCBUILD] Compaq upgrade question I'm new-hope I'm doing this right. I have a Compaq presario 5006us with a intel celeron 766 mhz processor. 383mb memory-pc100,168 pin dimm,sdram, two hardrives 40gb, one 20gb. I need to upgrade to have a least 800mhz for work purposes. Is it better to get a new motherboard or a new processor and what's the difference? I've been told that my model should take up to 1000mhz pentium processor. I've looked at a few ads for motherboards and am just confused by everything. I have a limited budget, and only @ $150 to spend on this, and am looking for the best route to go. Also I was told to have someone who had done it before install the processor rather than trying it myself. Is it the same with the mother board? carmen strickland PCBUILD maintains hundreds of useful files for download visit our download web page at: http://freepctech.com/downloads.shtml