I just replaced my hard drive and diid a new install. I now realise i left a couple of files i didnt back up.
my question is , am I ok to replace my old drive boot up , then export the foiles then put back my new drive .
its seems logical but im worried the pc will throw a fit and not be able to boot. thougt id ask before i try :)

Why not just add your old harddrive to your existing setup?

i want to run fire fox to export password files , i thought i had but seems i either didnt or lost it

You could install your old drive in a USB external case and then access the files from there.

Sure you reinstall the old hard drive and export your files to an external drive.

Another way to back up firefox files is to use firefox's SYNC this will store your passwords, bookmarks etc to google account and when you startup a new firefox and setup sync it will resync your files once again.

@pacav69 yes thanks i know that but was just concerned changing drives would mess up the bootmanager. i had tried cloning before but had issues with bad sectors so i reinstalled just cant track a few files.
i will boot the old disk, I just wanted to ask incase there was an issue i didnt know about, windows seems a bit skittish at times

ok i just changed drive and no problem. Just me being super cautious. thanks

@edbr the boot manager is not effected by changing drives