Fine, you just wanted to use a x64 OS, because you need to make a lot of calculations for financial softwares, make videos, to play or whatever else. You just forget that most of current applications are still in x86, with plugins in Explorer, providing right-click menu items, which, infortunately, won't appear in the x64 explorer, because the plugin is a dll which was x86 built and cannot be loaded by the x64 explorer...

This is possible with the Platform toolset available on the General tab of the project configuration. By default, you can target either VS2010 (platform target v10) or VS2008 (platform target v9).

The platform toolset selection is available as follow:

After a migration from x86 to x64 on Misys Risque, one of the biggest deal was to find a tool able to check the memory leaks and access violations (buffer overrun and so on..). This was done one year ago, but I think that nothing has been changed since. I tested different tools and this is the results of my analysis: