A Jenkins project which has been created and cloned on a Windows master cannot be deleted if the changes have been viewed. It appears that the changelog.xml file is left open by the plugin, which prevents deletion of the project on Windows.

Steps to duplicate the problem:

1. Create a new free-style Jenkins project - mine was "check_git"
2. Use the Git plugin with that project - I used https://github.com/MarkEWaite/check_git.git as my URL
3. Build that job at least once
4. Click the "Recent Changes" link in the project
5. Attempt to delete the project - fails on Windows (OK on Linux)

The error message reported is:

jobs\check_git\builds\2013-11-14_06-58-41\changelog.xml: The process cannot access the file because it is being used by another process.

A similar job does not have any issue deleting on Windows with a Subversion SCM provider. The issue seems to be specific to the Git SCM provider.