.NET Framework 32bit & 64bit on the same server?

Hi All,

I have a Windows 2008 RS server with 64bit .NET 4.0 framework.

We have a few .ASP Sites developed using 4.0 32bit framework, and new sites being created using .NET 4.5 32bit framework.

Do I need to install 4.5 32bit framework on my 64bit server, or will the 64bit 4.5 framework work?

Thanks,