Windows

Regclean will scan your registry for known errors and will attempt to fix these errors. If it doesn't know of the error then it will not attempt to fix the error. It is a good tool but will not fix a corrupt registry. The CD-Key for windows can be found in:
-Control Panel
-System
-General Tab
-Registered to:
registration name and number is located here

There is a program called Service Pack Query that will give you the SP info. Email me and I can send it to you. As for the DHCP, you would set up another server on the second subnet to be a DHCP Relay Agent. I know that would work, whether there is another solution I am not sure, that is the only one I've tried.

U ask so many questions in one shoot.

1. I don't know. Normally 128-bit is only available in North America.
2. U can use "User Manager for Domain" to remotely open the NT wkst/srv/domain user account.
3. I don't know. The above proposed may help.
4. If u use MS DHCP, it's not possible. Unix may be.
5. There is one utility on NT Resource Kit call SRVINFO, it show some NT information also Product ID. U can also search in the Registry as in the above proposed.

1. 128 bit Service Pack 4 installs the Protected Storage service. 40 bit does not.
2. User manager for domains
Remote viewing package
Rcmd
Tons of third party apps
3. Removes Copious data from the registry
4. Assign two IP addresses to the network card, one on each subnet. Create two scopes.
5. Right click on My Computer.

1. Review the version tab on the properties for the schannel.dll file...if it says "Export version" it is 40-bit, US/Canada = 128-bit.
2. Can be done with "User Manager for Domains", connecting to the remote computer name for the domain.
3. Cleans out inconsistencies it can find in the registry.
4. TCP/IP can be configured for multiple subnets using static addresses in the Advanced section of the TCP/IP properties. Using DHCP for multiple subnets on one NIC may not be an option.
5. Right-click on My Computer and choose properties. The CD Key matches the middle 10 digits in the Registered to: number.