When installing TFS2010 (or upgrading on new hardware) with SharePoint Foundation (wss 4.0) it can not be done with the installer setting up wss. You need to install and prepare SharePoint before configuration of TFS. This can be done as described in the following blog post:

http://myalmblog.com/2010/12/20/installing-tfs2010-with-sharepoint-foundation-2010/

There is one added security setting which you might have to tweak also in SharePoint Foundation and which has been changed since wss 3.0. You need to change the security on files other than aspx to "Permissive". The default security setting is Strict, which gives you the:

 "Do you want to save this File"

when you try to access html files. E.g. the wiki.

How to change to "permissive" security is described in the following blog:

http://blog.brainlitter.com/archive/2010/05/19/sharepoint-2010-treats-pdf-and-other-file-types-as-insecure.aspx

One further note if you want to use EMC SCRUM for Team system v.3 on SharePoint Foundation 2010 and get the error:

TF249033: The site template is not available for the locale identifier (LCID). The site template name is: SCRUM

Then  apply the fix in the following post:

http://consultingblogs.emc.com/crispinparker/archive/2011/01/14/scrum-for-team-system-v3-sharepoint-2010-portal.aspx

And remember to change the powershell script line with the suggestions in the blog comments ("LiteralPath" instead of "FileName")