[inventor_phild]

If you get the message "Component x is not checked out to you. Edits are not allowed on this file." then the file was saved using Autodesk Vault.

One thing to check is what Project file you are using.

1. Open Autodesk Inventor.
2. Assuming you are using 2011 or newer, click Projects.
3. Select Projects.
4. Check the project file is Single User. See attached image. If it shows Vault then you need to create or use a different project file.

Let me know if this solves the problem.