Maybe this will help some people here.
Windows 10 had turned "FAST BOOT" on in your settings a while back. LONG story short, when you do a "SHUTDOWN", it sort of HIBERNATES instead, leaving your gummed up corrupted memory "kernal" STILL a hot mess the next time power it back on. A actual RESTART should take care of it.
I mention because it could be secretly affecting how well Vegas runs on your system. I've turned it off and never looked back.
WINDOWS 10 SEARCH: Power & Sleep
> Additional Power Settings
> Choose what the power buttons do
> Change settings that are currently unavailable
> UNCHECKMARK: Turn on fast startup
Your next SHUTDOWN will clean house, and you won't be dealing with a potentially corrupted hibernate loaded system.