There may be an occasion where you want to test Revit 2011 with add-ins disabled.
By default in Revit 2011 products the Add-Ins components have been moved from the Revit.ini file to a separate location. While you can still utilize the Revit.ini for this release, the default location is now listed below.
If you want to test Revit with all add-ins disabled [or selectively disable add-ins] follow the steps below:
1. Close Revit 2011
2. Locate the following folder:
Windows Vista \ Windows 7 - C:\ProgramData\Autodesk\Revit\Addins\2011
Windows XP - C:\Documents and Settings\All Users\Application Data\Autodesk\REVIT\Addins\2011
3. Temporarily move the add-in files from the folder above to another location.
4. Launch Revit 2011; add-ins will be disabled.
When testing is complete you can move the add-in files back into the original folder.
There are other approaches to disabling add-ins as well. I've included Jeremy Tammik’s The Building Coder blog below, which is an excellent resource for the Revit API:
One specific post expanding on this issue: