Thoughts on technology

My darling-and-beloved laptop (a Toshiba Satellite) is somewhere between three and four years old. It's served me well and has had no major problems. It's still serving me well, except that in the last couple weeks something has happened to make the svchost.exe file take up 100% of the CPU. It'll do that for ten or fifteen minutes (during which things either run very slowly, or don't run at all), then be fine. Usually it happens just at startup, but sometimes at other random times as well. It's getting annoying, and I'm sick of it.

I ran full scans with Ad-Aware, ewido, and AVG. Ad-Aware found a few things, which I deleted, but the problem is still there.

So, two questions: any other ideas before I take it to the shop?

and

When/if  I take it in Monday to have it professionally scanned and cleaned, shall I tell them to go ahead and put an 80 GB hard drive in it? It only has a 20 GB now, which has been fine, but with all pictures I take some extra room would be great. (side note, because I'm honestly not quite sure...will a larger hard drive just give me more space to store things, or actually make it run faster? Or do I need more RAM, as well? It runs normal things fine, but programs like Photoshop are a little slow sometimes.) Like I said, it is around four years old. I will be needing/wanting a new one sometime in the next few years. Since it has no problems except for the one thing now, I don't see a reason to ditch it for a new one yet, but I don't want to put too much money into it if it'll probably only last another year or so.

Give me imput!