Computer help please

[Dead Eye]

If you just want bookmarks then I'd suggest making use of Firefox's Sync feature (requires an account with them). If it's an up to date version of Firefox you should find Sync under the menu in the top right. Set this up under your old windows account first and wait for the sync to finish, then sign in to your new account on Windows and sign in to your Sync account on Firefox.

I use this myself so that bookmarks and history are shared between my home PC, work PC, laptop and mobile phone