Some computer conundrums

Usually, I'm the guy people ask for help with their home PCs, but lately I've run into a few strange things, and for all the googling I've done, I can't figure out what's going on.

1. A Dell Inspiron 4000 laptop, running Windows XP Home, will freeze up for minutes at a time. Everything stops -- the clock stops updating, the video screen freezes, keystrokes and mouse inputs are ignored. The display stays on, unchanged. If the disk access light is on, it stays on; if off, it stays off. Eventually, it seems to come back to life. I thought it might be CPU throttling -- slowing the CPU to keep the temperature down -- but the CPU is staying cooler than 45 degrees Celsius. The computer is not just busy -- if it were busy, then the keys I type would be buffered and displayed when the CPU yields time to other processes, but in this case the keystrokes are lost. It's as if time stops and the CPU is in suspended animation. It isn't consistent -- it's very bad some days and hardly happens other days. Seen anything like this before?

2. At home we have a remanufactured Dell Dimension 2400, which we bought from the Dell Outlet online for pretty cheap. This too is running Windows XP Home. The kids use it, so we've tried to run some of their older games. The games from Broderbund won't run unless we set them to run in Windows 95 compatibility mode. The games will then run, but the video display for all programs appears upside down as long as one of the games is running. Stop the game and the video returns to normal color depth and resolution and is back to right-side up. Anyone seen anything like that before? The monitor is about 10 years old, a NEC Multisync 4FGe.

3. Norton Internet Security (NIS) 2002 was interfering with the Internet. I had to reinstall Norton Anti-Virus, and apparently it reinstalled NIS 2002 at the same time. It had an effect on my ability to view websites with anti-bandwidth-theft devices installed. Sites like Ephemeral Isle and AllahPundit are set up to prevent other sites from linking directly to their graphics -- a graphic can only be viewed if the referrer is a page on the same site. With NIS 2002 installed, even though not activated, I could not see the graphics on the pages on these sites. After I used Symantec's removal tool to get rid of NIS 2002, I could see the images. Oddly enough, I still can't do a live update for Norton Anti-Virus from that machine, although it gets further in the process than it did when NIS 2002 was still installed.

If anyone has a lead on an explanation for what I'm seeing, please drop me a line. Thanks in advance.