I monitor technical support channels at Stardock on occasion and whether it be games or non-games, it seems many people, even in the age of Windows XP, tend to reboot their computers far more often than is necessary.

Generally speaking, you shouldn't have to reboot your machine. Even if it seems "hosed" odds are you just need to restart some program.  This guide is by no means comprehensive but it's a good start in getting you to not have to reboot.

1) Restart Explorer.  If all else fails, particularly if you're someone who customizes Windows, kill the shell (typically explorer).  To do that, hit Ctrl-Shift-Esc and then go to the process list. Then select explorer.exe and kill it. Then go to the file menu and run explorer.exe to bring it back. This will solve many of your problems.

2) If your system is getting bogged down, odds are the Internet Explorer has slowly taken over. Kill off iexplore.exe processes left and right and you'll probably find your system coming back to a level of sanity.

3) Go to the task manager's "view" menu, choose "Select columns" and add virtual memory, handles, and GDI objects. Then when they're added as column headers, click on them to sort the processes by them. Find ones that are using a huge amount of them compared to the others and kill those processes.  Beware, svchost.exe are wild cards. Killing them might kill your system. So kill those only as a last resort (that's where the "0 foot print" msstyles engine runs).

4) Keep your video drivers up to date. This may seem like a hassle but usually if you're running into weird video issues it's driver related. That, btw, does not mean running out and downloading the latest version when it first comes out.  Let someone else be the first to try them out.  What I am saying is that every half year or so you should check to see what the latest version is and get them.

5) Use MSConfig.exe (run->msconfig.exe) and go to the Start-up tab.  There's often a LOT of crap that gets put in there. If it looks like junk, it probably is, try de-selecting it and then it won't boot next time. Very few things need to be loaded on start up.  Quicktime, display panels, sound driver panels, and other junk can be removed to save quite a bit of memory. There's also usually plenty of registration programs floating in there.

Follow these 5 things and odds are you'll rarely have to reboot when you don't want to.