Lately I'm seeing a fair amount of posts for people wanting to add XP to their Vista or Windows 7 system creating a dual boot environment or to completely replace Vista and 7 with XP. Personally I think that's a bad idea for multiple reasons. Here are a few of them:

1) Driver support. XP is not really functional without drivers from the manufacturer as compared to Vista and 7 both of which have more drivers built into the operating system. If you can't find drivers from your computer's manufacturer specific for XP don't even try it. The result will be a system without good graphics, internet, or sound, just to name a few.

2) Lack of security and other features. I found an article that highlights some of the new operational, visual, and security features introduced in Vista and further refined in 7. Maximum PC | Windows 7 Review: XP vs Vista vs 7 in 80+ Benchmarks

3) Better gaming graphics. Both Vista and 7 come with newer, more advanced versions of Directx than is available for XP so if you have a game that takes advantage of the new versions of Directx you should stay with Vista or 7.

4) Different, incompatible bootloader. Whereas the first 3 points also apply to replacing Vista or 7 with XP this point particularly applies to attempting a dual boot with XP. XP uses a different bootloader than Vista & 7 and the XP bootloader doesn't know about either so if you install XP on a Vista/7 system only XP will show up. It is possible to restore the Vista/7 bootloader from XP but it is very tricky and you'll have to use a third party program. If done incorrectly you'll wipe out the bootloader and not be able to boot into XP or Vista/7. Only advanced users should even attempt the procedure. I've actually done this and the first time I did wipe out the bootloader but thankfully I was able to get it back. I'm not even going to discuss how to do this because I don't believe that it should be done by the average user.

I cringe anytime a read a post on someone wanting to do a dual boot or "downgrade" their Vista/7 system with XP. There is really no need unless you run really old 16 bit programs or have extremely old peripherals (such as printers) for which there are no Vista or 7 drivers. If this is for program compatibility you might consider installing XP as a virtual machine using either Microsoft's Virtual PC, Vmware, or Virtual box (note that for Vmware you'll first need the workstation trial to create it and then after that you'll install the player). There are other programs but those are the ones that I've used. Running old printers should work through Vmware Workstation because it shares USB ports with the guest machine.

The only other reason would be a lack of ram but most computers made in the last 3-4 years should have enough ram especially for 7.

If I had any suggestion, it would be to put security first because that is what Microsoft has done, and rightfully so, thanks to the badguys.

XP was designed with legacy (old hardware and software) support as a priority. This was due to the corporate world insisting XP would not force them to retool (buy all new hardware) and re-program (port) all their custom applications and data formats - a very expensive process they had to do before with CP/M to DOS and again to Windows 3.x and to Windows 95/98. Microsoft listened to their largest client-base and designed XP 10 years ago to support hardware and software designed from the DOS era of 20 years ago - a time when security was not an issue.

About the same time, Microsoft was ordered by Congress and the European Union to NOT include anti-virus in Windows. This was due to Norton, McAfee, CA, TrendMicro and the anti-virus industry whining, crying, and insisting it was their job to rid the world of malware. We see how well that worked. Of course, they have no incentive to rid the world of malware as that will put them out of business.

After a decade of relentless bashings and blame for the security situation caused by the badguys, Microsoft decided no more! So Windows 7 was designed with security first. That alone is reason to let XP go!

Windows 7 was also designed to support and take advantage of today's modern, and future hardware and software. Like every operating system before it, Windows 7 likes lots of CPU, RAM and disk resources. But at the same time, hardware prices have dropped significantly and/or hardware performance/capacities have increased significantly.

Ideally, your favorite XP programs should have new, Windows 7 versions that by themselves are more secure. Alternatively most XP era programs will work with Windows 7 as is, or in compatibility mode. And advanced versions of Windows 7 have Virtual XP Mode.

If you have a program that is so far outdated and Windows 7 support has not been provided, then it is time to look for a new alternative program. If you have an XP program you cannot upgrade and cannot live without, I recommend that be used on a separate machine, dedicated for that purpose. Then use a second computer with Windows 7 as your primary computer for all your other on-line activities (banking, school, email, surfing, etc.).

Thanks for your advice and complete reasons to not try to dual boot XP with my installed Windows 7. This is the first good information I have received.

I'm glad it has helped someone. That gives me a nice, fuzzy feeling inside.

I agree with the security aspect and that programs if they aren't compatible should be upgraded however that isn't always feasible (if not possible) especially in the corporate world. My employer is still using XP on most of our systems for compatibility reasons. As for XP compatibility mode, that didn't work for me. I had a permissions issue that I couldn't change which prevented me from running it.