Can XP be tweaked to do this?

[caporion]

Hello,
I've been playing around with .net server beta, XP Pro and NTswitch and I was wondering if it was possible to tweak XP Pro to allow a locally logged in user and one logged in using Remote Desktop simultaneously? I have been able to use NTswitch on an XP Pro system to make it possible but I JUST want the capability to have the two users simultaneously and not all the other stuff NTswitch does. Anyone know what Registry keys need modifying to tweak XP Pro to do that? I've been trying to compare 2 exported registry files one before and one after using NTswitch to see if I can isolate the keys but so far no luck.

[Sephiroth]

I don't think it's possible. Here is the best explination I can give as to why. *I breaks out pages of notes saved on CD-R from when I first messed with NTSwitch and looked at the differences between server and workstation and published the article on ADTW.*

There are two keys in the NT registry that differentiate a server OS between a workstation OS. Normally, you can not change the values in these two keys.

The first key is

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Contro l\Product Options\ProductType

There are three possible values (as of NT4 and Windows 2000, could vary in .NET) that this key can have. If the value is WinNT, then it is considered to be NT Workstation, 2000 Pro, XP Home, or XP Pro. If the value is ServerNT, it's considered to be NT Server or 2K server. And if the value is LanmanNT, then it's Advanced Server (mabye .NET ADS too? I'm not sure)

The second key is

HKEY_Local_Machine\System\Setup\System Prefix

I'll just paste a quote from this article as to what that key does as it explains it far better than I could....

The SystemPrefix value is a binary value which the kernel treats as two DWORDs, of which the only important piece of information seems to be the bit represented by the mask 0x04000000 in the high-order DWORD. If ProductType is "ServerNT" or "LanmanNT", then this bit must be set. If ProductType is "WinNT" then the bit must be off (any inconsistency results in a blue-screen error at system boot).

You can't normally change the values in these two keys. If you do, Windows will give you this message:

"The system has detected tampering with your registered product type. This is a violation of your software license. Tampering with product type is not permitted."

You can change the keys yourself and watch what happens. From NT4 up Microsoft added safeguards into NTOSKRNL.EXE which watches these two keys. If the threads detect a change of the key, NT will give you the message above and change the values back. You can change them, click ok on the message, and manually do a refresh in the registry and see them changed back.

The way that NTSwitch gets around NTOSKRNL is this:

First it creates a dump of your entire NT registry. Then in the dump it will change the two keys, not in the registry actively being used. Then, once you reboot, it will delete the registry hives and replace them with it's altered ones.

From there, things get more complicated. NTOSKRNL, kernel32.dll, hal.dll, and a few other system files read the values of the two keys during boot.

If the value indicates a workstation OS, then the NT kernel is configured dynamically as a workstation during boot. This means 1 user logged onto the console at a time, limited version of IIS, only 10 HTTP connections allowed to the machine, BackOffice and other server apps won't install, etc.

If the value indicates a server OS, then the NT kernel is dynamically configured as a server. More than one user is allowed to be logged onto the console at the same time, server software will function (or just install as the case usually is and still function when you go back to a workstation setting), etc. Other things that vary in how the kernel is configured is cache sizes, ram usage policies, etc. as they will differ between what should be used for a workstation and what should be used for a server.

You won't find any other differences in the registry other than the two keys mentioned above. Everything else is done at kernel level. So, in closing, it's not going to be possible to do it with NTSwitch alone . There may be 3rd party alternatives that let you do it, but I'm not aware of any.

And if you fell asleep reading this post, sorry, I didn't want to just give you a no it can't be done either



Last edited by Sephiroth at Today at 7:13 pm

[Sephiroth]

And while I'm at it, welcome to BetaONE, I hope you'll be here for a while and enjoy the board

[caporion]

Wow that's some explanation. Thanks for being thorough. Hopefully sombody will come up with a utility to do this as it would be very cool. I think this will save me some grief in trying to "find" the elusive "magic key" to switch this on since it apparently doesn't exist. I like the .net server beta I have from MS in that it allows that and many other advantages over XP Pro but unfortunately it chokes when trying to detect some of my WiFi hardware and therefore is useless to me since I rely on a WiFi connection to LAN my laptop and desktop computers. Maybe .net RC2 will be improved to the point where I can use it. All I know it the multi user feature I mention is VERY desirable since it allows me to be on the desktop through Remote Desktop and my wife can be logged on locally at the same time. I like that because in XP, the desktop is basically useless to her while I'm on it from remote. Anybody who comes up with a way to do that in XP... thank you! For now I'll just wait and see. If anyone knows of a utility or another way to do this. Please post in this thread.

Thanks for the info and the welcome, Sephiroth!

[craftyc]

Perhaps if M$ could creat their kernel to be a modular one so as the (more advanced) user can add in options that he/she feels are suitable, much like Linux. This way caporian may be able to have his feature.



Last edited by craftyc at Today at 4:42 pm