upgrade has lost network

Hi,i have just upgraded mint 19.3 to 20.All seemed to go well but now i have no wired network.
I get a nag that says cable unpluged but this is a duel boot desktop & i am posting this on the
windows half,so no hardware problems.Network manager says last used about five minuts befor the upgrade finished,i am thinking did the final tidy up dump the network drivers?
Driver manager says it needs network to do anything!Can anyone help with this please.