Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We currently have a 64bit Windows Server 2003 running an instance of IIS 6 which was configured to run in 32bit mode. If we install the .NET framework 4.0, should the framework be installed as 32bit or as 64bit?

Note, this is a production web server which currently has .NET 2.0 installed and runs a classic ASP application as it's main website.

share|improve this question
up vote 2 down vote accepted

The architecture of the .net framework must be the same as the operating system you have installed. In your instance you will require the 64 bit version.

What actually happens on 64 bit is that you get both a 64 bit version and a 32 bit version, so your IIS application will load the 32 bit version.

You will need to configure your App Pools to run using .net 4 once it has been installed.

share|improve this answer

When you install the 64-bit version of the .NET Framework on a 64-bit system, both the 32-bit and the 64-bit ones get installed.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.