If you would like to know what's Extended ROM, read my article
here.
Please note that Extended ROM installation is not possible on all devices. Different devices use a different Autorun Method. Autorun is sometimes a small application that tells the device what softwares need to be installed in what order automatically after a hard-reset. Some have a feature of copying files whereas the others stimulate cab files to be installed.
Before you proceed, its advised to know what are the files and in what locations should they be for the software to work.
In Windows folder:
UTAv35.exe - Core Module
Tapilib.dll - Resource Library File
Uta_confige.dll - Configurations File
Rdui.dat - Registration File
In Windows/StartUp folder:
UTAv35.lnk - Shortcut to core module
GPS Plug-In files:
In Windows folder:
Gpsplg.exe - Core Module
Utagps.exe - Interceptor Module
Utagps.dll - Resource Library File
Monitor Plug-In files:
utamon.exe - Core Module
The above files when in place, the software will work as registered/activated and with configurations! Depending upon your device, you need to make these files available in place, either via custom cab file created with third-party softwares such as WinCE Cab Manager or via Direct Copy file method from Extended ROM after Unlocking it!
In some devices, the stupid signing security warning appears, preventing to start the application directly. In that case, additionally you need install this file
http://www.PocketPC-Live.com/ds.cab Through Extended ROM installation in the first place.
Good news for forum users: If you have your posts count over 50, we shall help you make the custom cab file ourselves

Happy participating... Even if your post count is below 50, don't worry, we will always try helping you with your queries here. Just reply to this topic and we shall be glad to assist you further.
Best Regards,
NiCK Carty, CEO,
CartyStudios Corp.
www.PocketPC-Live.com