I have a service stopping NT from booting.

A. Normally you can modify the start-up of services using the Services control panel applet or Computer Management MMC snap-in - System Tools - Services in Windows NT 5.0. When you modify the start-up of a service it actually changes a value, Start, under the Services registry key, HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services.

The first action to try is when Windows NT boots select "Last Known Good configuration" however if this does not work you can use the following.

The Start value of a service can have a number of values as defined in Q. What are the ErrorControl, Start and Type values under the Services subkeys?

In order to modify the start-up state of a service from outside of NT you will need to install a second copy of Windows NT on the machine (or if you can get the System file from the machine onto another machine using a tool like ERD Commanded (from http://www.winternals.com) the extra copy is not necessary).

1. Install a second copy of NT (minimal) to a different partition
2. Boot into the second copy of NT
3. Start Regedt32.exe
4. Select the HKEY_LOCAL_MACHINE window
5. From the Registry menu select "Load Hive"
6. Move to your original NT installation partition and folder and then to system32\config, e.g. c:\winnt\system32\config
7. Select System file and click Open
8. Enter a name for this temporary hive open, e.g. OrigSystemHive
9. Select the new hive, e.g. OrigSystemHive and select the "Select" key
10. Check the value of Default, this value is usually 1. This number is x (you'll see what I mean)
11. Now move to OrigSystemHive\ControlSet00x, e.g. OrigSystemHive\ControlSet001
12. Now under this key select Services and find your problem service and select it
13. Double click its "Start" value and modify, 4 would disable the service, 2 would set it to auto start. If you have a more complex problem changing the Type value may be necessary to alter when the service is attempted to load
14. Move back to the base, e.g. OrigSystemHive and select "Unload Hive" from the Registry menu. Click Yes to the warning box
15. Reboot into your original NT installation and your service problem should be resolved

You can now deleted your second copy of NT if you wish however it is always useful and takes up a minimal amount of space.

Another solution is to use ERD Professional which allows you to specify startup options for services/drivers from outside of NT, have a look at http://www.winternals.com.

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