Question : Why are .cab files failing to install on my movile device?

Using Windows Mobile 5 on an Samsung i730, all .cab files fail to install on the device and report,

"The file 'xxx' cannot be opened.  Either it is not signed with a trusted certificate, or one of its components cannot be found.  You might need to reinstall or restore this file."

The files (any file including microsofts own files) will not install regardless of the fact they are signed with trusted certificates and they are not corrupt.

What can I do to resolve?

Adam

Answer : Why are .cab files failing to install on my movile device?

I guessed you would be trying to avoid it, but some people don't have much on, so it wouldn't be too much of a prob... :)

I can't answer you 100%, all I know for a fact is that a factory reset will cause whatever OS is in the ROM to be reinstalled from scratch... If the install of the new OS was essentially a firmware upgrade (which I imagine it would be?) then you may be OK... Best thing to find out for sure would be to have a quick chat with Samsung... I'm not sure if the new OS install overwrites the CAB files that install the OS in the first place or not!

I also found this -

Problem
Unsigned .cab Files Fail to Install If Mobile Device Security Policy Is Set to Prompt
The unsigned .cab file policy on Windows Mobile 5 and newer mobile devices can be managed using the Security Policy configuration item. When .cab files are distributed using Configuration Manager 2007, the prompt for unsigned .cab files is suppressed even if the client .cab signing policy is set to prompt. If a .cab file is installed by the user outside of Configuration Manager 2007, the .cab signing policy will function as expected.

Solution
Sign .cab files distributed by Configuration Manager 2007 for installation on mobile devices.

See if it helps and let me know?

I certainly wouldn't do it without finding out for sure first though...

And, I believe I've had this exact problem before in the past... I'm racking my brains trying to think what I had to do... Oh and have you tried a standard reset as well, then first thing after restart tried running the CABs?