I'm running SW16 on a 7 yr old Dell Workstation with Windows 7.  This week SW became harder to use every day until Friday it was taking 5 minutes of CPU pegged at 100% just to dimension a single line. 

After using Dell Support Aps to diagnose no problems with my hardware I began to wonder if it might be a Windows issue and went to the Restore Ap.  What I found was a "Critical Windows Update" every day of the week.  Restored back to June 28 and it's back to normal.

There's no question here.

Just an FYI,

Jerry