SetPriority
SetPriority is a Windows utility that will let you specify beforehand which priority you want
your processes to have. Whenever a program is started that you have specified, SetPriority
will adjust that program's priority automatically.
SetPriority will sit in your System Tray and watch running processes. When a process
matches one on its list, SetPriority will adjust the priority of that process automatically.
For instance, if you always want Windows Media Player to run at high priority, you'd
specify that, and as soon as you start up Windows Media Player, SetPriority will adjust
it to run at high priority.
You can get SetPriority here.