Compaq Presario 1700T hard drive problem/replacement

Good evening,
I have an older compaq presario 1700T which is now having the error "no
operating system found" I am not very computer savy but with some help
can figure things out. I don't want to spend to much to fix it since
you can get a new one for $500.
Anyway, I have done some fiddling with ultimate boot up disk and the
restore cd and still could not get it working.
I found an identical hard drive on ebay in working condition with
windows me already installed. My question is whether or not swapping
out the hard drive on this model is as simple as removing the screw and
pulling it out and putting in the replacement? Is there anythign else I
would have to do or should it theoretically just boot up? my other
option is to take it to a professional and spend $120 for replacing the
hard drive and installing windows.
Any thought or help would be great.

Thanks
Nut

.