SSMS stops working while SQL Server still running

Aggh
Laptop Win7 SQL Server 2008 R2 SSMS has worked for a couple of months. Suddenly stopped working. SQL Server was still working becase VS-TFS still present.
Log file lookups on Web search suggested all sorts of possible directions to solve including:
Permissions on Network Service, Reinstall SQL Server performance monitors using unlodctr sqlctr.ini or something
Reinstalling SSMS did not work
Anyway what did work was Restoring back two weeks.