When I have several large programs running and the system runs low on memory, things get very flaky. Is this normal?

It's probably not memory you're running out of, but available handles or desktop heap. Dan over at Dan's Data has a page about other resource limits in Windows XP. I experienced similar issues until I upped the limits on this machine, which has 4GB of physical memory. My handle limit is currently set to 18,000, my system heap to 8M, and my desktop heap to 512k. I haven't had any troubles since increasing these values.

"Yes it is normal for Windows, especially when it has been running for several days. But, no it is not normal for a superuser to reboot when this happens. You should start closing things when you notice the machine getting sluggish, or the fan getting consistently noisier, or the drive rattling noisily on and on.

I general start by closing any extra Internet Explorer windows. Then I open up task manager, sort by CPU and see if something is popping to the top of the list too much. If so, I close it. If Firefox is running I kill the process in Task Manager because it saves the tabs and restores them upon restart. Also in task manager, look for processes with really big memory. They are probably causing too much disk activity by swapping in and out. With Google Chrome, I generally close tabs with known problem sites like Google Mail and Yahoo Mail. Sometimes I need to kill iexplore processes in task manager even though all the browser windows have been closed.

If I do this, I can usually find the culprit and still have half a dozen apps running with a dozen Windows open. If I closed up spreadsheets or word documents that I need, I can always reopen them quickly with the File menu choices 1, 2, 3, 4 etc. You can expand that up to 9 in the options, I believe.

All in all, I can usually sort out the problem without a reboot, and without losing much of my working context."