^^^ Well, mine is a vanilla install of the whole OS and it's happened twice. I've now created disc images of both the drive containing WinXP installation and another drive containing solely my plain FSX installation. Should guard against a future occurrence, at least.I believe a file somewhere is becoming corrupt during a crash causing the product to become deactivated and wreck subsequent reinstall attempts.

hmm...called microsoft yesterday and they expected a fix in a week...go figure it's already been 2 weeks...

Hmmmm... An error casued by a crash is possible, except mine didnt crash.All I had done is add the mod for the trees, and a couple of aircraft, and yes I have IE7 installed as well.... But have had since it came out, and FSX had been running fine for over a week after the latest mod I'd put in. It never crashed once, just de-validated itself somehow and decided it wouldnt work, told me to un-install it and re-install... and well, the rest is obvious.As far as I am aware, I didnt do anything to upset it, I didnt change any hardware, didnt update any drivers, didnt mod FSX, just played it...... As far as I'm concerneed, it was just completely random....

Am I correct in assuming that reinstalling the operating system is still the only solution to this problem (although it's probably inappropriate to call a complete OS reinstallation a solution and it's definitely not something I'm willing to do). I'd really like to be able to use FSX but with the lack of any acknowledgement of the error 1722 problem from MS, I'm getting close to taking advantage of the 45 day full refund policy.

I've done two WinXP reinstalls in the past 3 days...both thanks to FSX. With every installation of FSX other application shared DLLs get 'lost' - AVG Antivirus stops working, my Genie Backup software stops working, Adobe Photoshop Elements 5 stopped working...those are the ones I realized. I don't have a screen shot of the error messages I was receiving but i think it was something similar to "MFC71d.dll is missing". I reinstalled antivirus, but then FSX stopped working and I got the 1722 error after uninstalling and reinstalling.So I did a first reinstall and had FSX on a fresh WinXP install - it ran AWESOME! I love that game. But installing anything else that I use - antivirus software, backup software, etc. Caused FSX to stop working again. So I reinstalled WinXP again and am waiting for MS to come out with their installation patch before I install FSX again.But that begs the question - what about FSX is over-writing so many other program's shared DLLs. Cheers,Mike Lyons

My thought is that the anti-piracy programming in the software takes a snapshot of the system to see if it's still loaded on the same computer. Any significant change would set it off (I think Win XP does this). Perhaps the settings in FSX are a bit too sensitive...That's my guess..

I am one of those who had the install error 1722. This was on a newly built system just a couple of months old. It was built primarily for gaming as I have a backup system for everything else. Not much software installed except for AVG and hardware/peripherals/drivers/etc.Aside from the FSX install problems, I had been having an ongoing problem since I first built the system. I was getting a Bad_Pool_Caller 0x2 STOP message on restart/shutdown. Debugging showed an error with the KMW.SYS, which is the Kensington Mouseworks driver for my Expert Mouse Pro.I didn't know if the two problems were in any way related. I resorted to reformatting and reinstalling XP Pro SP2. The first time I did this, I launched the FSX installer right after XP finished installing(ie. without installing any of the automatic updates or drivers). FSX installed and I proceeded to install all my drivers, windows updates, and software. After that, FSX ran fine for awhile but the next day it unexpectedly crashed. I went to relaunch it and got some error saying that my activation was no longer valid. I tried doing a repair using the installer but then I got the same 1722 error. Uninstalling/reinstalling gave me the same error. On top of that, I was still getting the Bad_Pool_Caller BSOD on restart/shutdown.I decided to do another reinstall of XP. This time I went step-by-step, methodically installing drivers/software to see if I could track down the exact culprit(s) causing the problems.As before, I installed FSX immediately after XP installed. I then installed my drivers/hardware one-by-one. I did NOT install any of the windows updates at this time. I had a sneaking suspicion that on of the mixed bag of 65-66 updates that are available was causing a problem.Longer story a little less long, I was able to install everything I had originally(minus windows updates) and I no longer have the Bad_Pool_Caller error or any problems with FSX for at least a week now.I have slowly started to install windows updates, one at a time to see if any of them cause the problems to return. I've only installed about 5 of them so far and will continue at a snails pace. I continually run AV and AS apps to make sure I am not contracting any malicious software in the process.So far, my machine is running very stable and the only thing I haven't done that I did before was install all those windows updates. In conclusion, I wish I could know for sure which, if any updates were the cause, but only time will tell as I get through the next 60 or so.I'm thinking though, that for anyone else who is having the install problem, that perhaps you may want to go into add/remove programs and uninstall all those windows updates. You can always reinstall them. This is something that I didn't think to try before I reinstalled windows. Although, even if the problem is one(or more) of the updates , uninstalling them may not fix the problem as the act of installing them may permanently damage something that prevents FSX from installing. Just a WAG though.I don't know why the windows updates would/could be causing this problem. If I go by the assumption that most of us install all those updates when they are released, then why is this problem much more prevalent? Maybe it's a combination of factors/variables that conflict with one of the updates making it a very sneaky problem.My hope is that I'll end up finding that "magic bullet" update that starts causing the problem and I'll be able to at least reproduce it on my machine. Until then, the mystery endures.Good luck!

Great post and an interesting thought regarding the possibility that a specific windows update may be the root cause of this issue! However, the question is why fsx is working on some PC

I was pleasantly surprised when I received an email yesterday from a member of the Microsoft Flight Simulator Team in response to a message I sent to [email protected] regarding the error 1722 issue that we're experiencing when trying to reinstall FSX. I've provided the fsinstall.log and sldl.log that he requested so at least there's a chance that this information will help MS get to the root of the problem. I don't really understand the information in the log files but it does appear that the problem is somehow related to a failed license installation.Since it appears that someone who actually understands the software is working on this, I'm feeling better about holding off returning the product for a refund for a while longer.

You guy's can also look here for help.http://support.microsoft.com/ph/11941http://support.microsoft.com/kb/829359

Had a phonecall today from a very nice lady at Microsoft Support. Told me they hope to have problem fixed in next 2 to 3 days. They will E-Mail Me.

I also have this problem.oh oh oh!

I hope they find the cause soon. The demo plays well on my machine and I'm really looking forward to being able to play the full version...if only I could get it to install.Must...be...patient (what was I thinking paying for overnight shipping?)

Any word from MS yet Simon???We all waiting on this "fix" :)

I got an indecipherable message left on my answerphone from MSN Support. I took the advice off another thread on the same subject and E-Mailed a Dave Templin on the address below. He sent me a tool that you use except I cannot get it to work. I have E-Mailed him back for further help. Give him an E-Mail he got back very quickly. Address at bottom of this post.I cannot use the tool maybe because of ignorance rather than it does not [email protected] this helps Simon