Windows Freezes

I have a 400Mhz PII with 96 RAM. Just recently my PC has started to temporarily freeze up. It usually only last for about 15 seconds before it “releases” and is useable again, but it is happening more and more lately. My browser is IE 5.0, but that is not the only app to freeze. When it does happen everything goes, what ever sound maybe playing at the time skips and my mouse sticks where it’s at.