Gateway M-1634u laptop CPU Support

They should have been more clear, but what they said is more or less correct. Upgrading a laptop CPU is complex and relatively dangerous (for the computer anyway).
Mainly because it wasn't intended to be upgraded, so info on how to do it is spotty at best.

Upgrading RAM and taking a SSD is the only thing that you can do (and usually do quite a bit of difference)

Now, some tips in case you want to proceed anyway:

-socket: your socket is S1G1, only processors for S1G1 will work in there, the linked one is for S1G3 and is very very likely to not work. From the page you linked, they are kind enough to list all processors that can go in that socket, and the best one you have some chances to put in there is this, which is 2.4 GHz instead of 2.0, but otherwise the same. My opinion? Not worth the risk.

-heat: the heat rejection system of the laptop is designed to work with the currently installed CPU, and it usually has little if any margin for improvement. Look for what they call TDP (Thermal Design Power), which in your case is 35 watts. Processors with a higher TDP are very likely to melt down everything.

-info: taking apart safely a laptop is tricky, having a service/disassembly manual helps a lot. Google extensively before you try

-caution: especially if you don't have enough info, when you encounter something that you cannot figure out, stop. Better keep a not-stellar laptop than turning it in an expensive paperweight.

Thanks, I missed the S1G3 part. For some reason my brain was reading S1G1 on it as well. And yes, I am familiar with taking laptops apart and rebuilding them. I actually run a very small business in computer repair. I actually prefer NOT to mess with laptops though. I do Mac and PC and the occasional PS3. I had already looked at the TDP and they matched pretty well, both at 35. This specific laptop is rather interesting though, as the RAM panel on the back, actually opens up for the CPU and the CPU fan as well, so you have access to all the major components. Don't really see that too often from the manufacturers, as they seem to like to make it as hard as possible to play with anything in there. You ever get a chance, look up this specific model, it's pretty unique in design.
And thanks again for pointing out what I looked over, much appreciated!

lol, you don't indicate the laptop name/model. just the CPU.