To expand on Dave's suggestion, when you bring up the Windows Task Manager, you should be familiar with all the programs in that list. If you're not sure what one of them does, Google it for an explanation. If it doesn't need to be running, kill it - it's just eating up memory.
Just about every program you install will want to run when Windows starts (that's why whenever you install ANY program you should choose CUSTOM instead of TYPICAL, so you can turn that feature off before it's installed). I use a free program called
Startup Inspector for Windows to tell me what's set to run on my system at startup. There are some apps that will try to run at startup even when you explicitly tell them not to, like QuickTime. There are others that try to hide themselves from Windows' Task Manager so you can't turn them off. Startup Inspector catches all of them, and allows you to remove them from the startup menu one-by-one with an easy to understand GUI for idiots like me. I've been using it for years and I love it.
When I go to record I will still bring up the Task Manager and make sure everything that doesn't need to be running is shut down (there are even some Windows processes that you can shut down as well - again just Google for an explanation of which apps you need and which you don't). Anything you can do to free up resources will make your Riffworks experience more enjoyable.