Run out of virtual memory after added to triple physical RAM and change SQL Server memory option?
I believe your virtual memory should be, at minimum, the same size as your physical memory.

I once had a new server deployment that had tested well, but performed terribly under a full load. MS got involved, and finally figured out we had a 16GB page file, with 128GB physical memory. Their recommendation was that the page file be at least 1.5 times as large as physical memory.

Bumping our page file size up to 192 GB got performance back to normal. Not sure if 1.5 X physical memory is truly required (in fact, I doubt it), but page file significantly less than physical memory does seem to be a Bad Thing.

NOTE: Our system at the time was Windows Server 2008R2, SQL Server 2008.