The way to transfer presets from one pc to another is to export the settings from the registry (that's where they are stored, not in the Vegas folders) and then import them on the pc.

You can do a search on the registry using one of your preset's names to find where they are stored. For directX presets, I think they'll be stored here:
[HKEY_CURRENT_USER\Software\DirectShow\Presets
So you can export the Presets branch and you'll have all your presets stored in a .reg file.

With render templates it's a little different. You might have to copy files (.sft) from your drive as well as get a branch from the registry.

On your new pc, you just double click the .reg file and the presets should be available next time you open Vegas.

This method will work to transfer presets between users too. (If you log in as a different user, all your presets will be gone)

But it looks like you might be out of luck if you can't get into windows. If you lost the registry then you lost your presets.