Set Default Programs before sysprep?

This does't seem to carry over after sysprep.

So similarly, any good options for mass deployment of default programs?

So far I've been testing GPOs to no luck. Using user policy, control panel, file options, replace, docx file extensions and then I've tried the winword.exe location in both c:/program fles and %program files%

Did I ask in the right forum?

Right now it's looking like I'll need a reg script.