I have been searching for something like this for a while. What I want is an app that can prevent specified processes from paging out. I will settle for anything at this point. Thanks.

By paging out do you mean connecting to the net?

na, I mean an app that can prevent selected processes from writing themselves to the page file instead of staying in the RAM. There are some apps that I always have running that get written to the page file, which causes the process to have to be rewritten back to the ram when it is called again. this causes a severe slowdown since my hard disk is not very fast.

There's an age old "tweak or non-tweak" and I have no idea if it works in Windows 2000/XP/Vista so make a system backup first and backup the .ini file that must be edited before mucking with it.

It's called: ConservativeSwapfileUsage

Note:
Using ConservativeSwapfileUsage can cause programs to that never crashed to all of a sudden crash allot! It's better left alone and to use the Windows default setting!

Edit:
Bleh, nevermind it's an old legacy hack for Windows 9x only.

If your hard-drive is that slow that you notice the paging, would it not be more beneficial to buy a new HD ?
I don't know your circumstances, but rather than trying to override the default behaviour of Windows apps etc.
IMHO