The Windows subkey under the following path defines some values used by applications created to run under Windows for MS-DOS:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
AppInit_DLLs REG_SZ
Causes all the specified DLLs (one or many) to be attached to all Windows-based applications. This means that once this is set for a session, upon restarting the system, all the Windows-based applications that run in that session will load the specified DLLs. For example, an applications developer can use it to attach the Microsoft Call/Attributive Profiler to all Windows-based applications by calling CAPSETUP.EXE, which sets the AppInit_DLLs so the user doesn't have to do it through Registry Editor.
Default:
DeviceNotSelectedTimeout REG_SZ Seconds
Specifies how much time the system waits for a device to be switched on. If the device is not switched on during this time, the system won't print to the device. For some devices, the system immediately posts an error message if the device is not already switched on. This entry only defines the system default value. To change the value for a particular printer, use Print Manager.
Default: 15
Spooler REG_SZ Boolean
Specifies whether output to the printer is to be sent through Print Manager. Changing this value to No turns off Print Manager.
Default: Yes
swapdisk REG_SZ drive:directory
Provides the name of the disk drive and directory to which Windows for MS-DOS in standard mode swaps non-Windows–based applications.
Default: The directory pointed to by the TEMP environment variable; if there is no TEMP variable, the default is the boot directory of your first hard disk (usually C:).
TransmissionRetryTimeout REG_SZ Seconds
Specifies the default amount of time for attempted transmission retries. If a successful transmission does not occur during this time, Print Manager displays a message stating that the printer is not receiving characters. This setting serves only as the system default value. To change the value for a particular printer, use Print Manager.
Default: 45