Since the Lolipop upgrade my Pc intermitently fails to recognise my NEXUS 7

[davange]

Since the atrocious Lolipop upgrade my Pc intermittently now fails to recognise my NEXUS 7 . I have worked around many of the other problems , but now I have to keep re installing the driver to transfer files from my pc ( windows 7) . What was a good tablet is now ruined by continuous issues and random problems