Hi cranheim,

This issue could happen after the windows update and in the following scenarios mentioned in this article
Windows live mail stops responding .
Try to run this Microsoft fix-it .

If this does not help, you can repair Windows Live Mail. Prior to this step, it is recommended to export the emails. Here is the link for Backup and Restore Windows Live Mail . Please follow these steps to perform the repair:
1. Click on Start button
2. Type 'Run' in the search box and click 'Run'.
3. Type the following command: C:\Program Files (x86)\Windows Live\Installer\wlarp.exe
4. Click on OK, and wait a few seconds.
5. Depending on your user account settings, you may see a User Account Control prompt, asking if you want this program (Windows Installer) to make changes to your machine, click on Yes.
6. Another window will appear that will allow you to either uninstall or repair Windows Live, click on the Repair Button then continue. It will take approximately two minutes to complete. When the repair is done, close all of the programs and reboot the computer.

Hope this helps.
Please reply if you have any further questions.

Thanks and Regards,
Manpreet C