Hi Charles,
Welcome to Microsoft Community.
As per the query, I understand that you are receiving error code 0x800f081f. I appreciate your efforts to resolve this issue. I will surely help you with this.
Please assist me with the following information related to this issue:
- When exactly are you getting this Error message?
- Are you facing any issues with installing windows updates?
- Why are you trying to install .NET frame work?
Please refer to the following Microsoft Help Article on how to Remove and Reinstall .NET Framework.
http://smallbusiness.support.microsoft.com/en-us/kb/976982
Note: Refer the section under Method 2: Repair the .NET Framework from the above mentioned article which says “use the .NET Framework Cleanup Tool to uninstall multiple versions of the .NET Framework, and then reinstall the components".
Also refer Method 3 to uninstall and reinstall the .NET Framework.
Try these steps and let us know the results for further assistance.
Thank you.