visual studio 2010 - Safely using existing vs2010 sp1 after installing vs2012/13 -

visual studio 2010 - Safely using existing vs2010 sp1 after installing vs2012/13 -

i have researched topic , discovered that:

you can install vs2012/13 on same machine running vs2010 sp1 you can target .net framework 4.0 current projects , run them locally

the problem arises when deploy websites servers not have fixes bugs in .net 4.0 made when installing .net framework 4.5 on local machine.

my question is, best way can create sure can next using same machine:

i can still run old/current vs2010 sp1 projects without breaking locally or when deployed remotely i can create new solutions using vs2010 sp1 targeting .net4.0 framework safely i can create new solutions using vs2012/13

if cannot have scenario above, using visual studio online help? (i have not had much read on visual studio online) thought alternative above?

visual-studio-2010 visual-studio-2012 backwards-compatibility