1. Backup Backup Backup. Backup your computer and especially if it is running great. There is some great software out there for this purpose. Acronis 11 Home comes to mind. That's what I use. Well Now! Allegedly you can back up in minutes instead of hours.
2. Do not use Windows XP restore unless it is next to a last resort. Which of course is wiping your harddrive. Twice I have used the restore function and it resulted in DL errors and of course had to wipe the drive. Some players have the restore function turned off. You can also use the repair function of Windows xp first if by that time your system can read it.
3. If you delete drivers for your soundcard or your video card use a driver cleaner. I've seen this oft mentioned. Don't take this advice lightly. It can make the difference in enjoying your new hardware or suffering through some disfunction.
4. If you take out an optical drive for any reason and then put it back in go to the bios to make sure it is selected. It probably will even work without being selected but if you have to do a restore the system may not find it.
5. Make sure you have all your Code keys. You can download software that will tell you what they are in case they are not handy.
6. Keep your system clean. Enough little spybots on it and it will suffer. Skuzzy has an excellent post on this called "Hints and Tips" that will help you to not get so many. If you build a new system, after setting it up, defragment. For some reason this needs done. I think because of all the programs you load. Trust me it will need it. I've built 3 machines in the last 9 months and they all needed defragmented shortly after the build was complete.
7. Use a separate sound card. I've said something different in the past because I thought my E8400 could handle it. It can, but there's a big performance boost if you don't use on-board sound. Additionally, if you over clock your CPU I believe on-board sound interferes with the cycles. Now I have no stats on it but that is what I believe. I put an new sound card in tonight and wow. It lowered my usage at desktop by about half.
8. Read Waffles post on Video cards. Excellent write up. I followed it and was rewarded with increased performance. That was even after I overclocked my video card which is a Radeon HD3850. Also, and this is way to simple, if you have trouble seeing turn up the brightness on your monitor. You can also play with the gamma in your video card software or in the game. I'm still not totally sure of the consequences though.
9. Get some rudder pedals. The twisty stick is for the lazy. Guess I'm pretty lazy, I've used the twisty stick for about 12 years. Rudder pedals take some getting use to. Since they are separate from the stick you don't inadvertently calibrate the other axis at the same time. I have heard people complain about how did that guy turn like that, That's impossible! Not with rudder pedals. Your not fighting the other axis to get it to turn. Further they have much more control. You definitely have to relearn to fly though and land. I crashed a lot landing.
10. Last, ask for help if you are having problems or just need some folks to help trigger your solution process.
I know that Skuzzy and staff have been very helpful to me and many others. Also Baldegle, Fulmar, The Fugitive, Pudgie and many many more have all chimed in at sometime or another with excellent advice.
Most of you are quite Tech savvy but I think this post may head off trouble for some.