I am finding lately that when I have been working for more than a couple of hours the computer's responses slow right down until nothing will open. Usually I turn if off before it gets to that stage. When I come back to it later, everything is just fine. I am running Windows98, Intel Celeron Proc, 434mhz with 64mb RAM. Capacity 8gb of which 4gb is free. I use disk cleanup and defrag weekly. I was wondering if any particular sort of programme that I may have installed could create this sort of problem. Thanks.