Windows cannot find %windir%\System32\msdt.exe

I had the same issue and found this question first. However, the real cause/solution is not mentioned yet in this question, but it is mentioned here: Windows 7's PATH and environment variables are corrupted

Summary of the solution: make sure your path is < 2048 characters. Check in both the user variables and the system variables.

Normal NTFS Permisions on folder C:\Windows\System32\DriverStore\FileRepository\ are System - Full Control, and Everyone - Read & Execute.

I you really want to copy into this directory you can do the following:

• Right click the folder, click Properties
• Click the Security tab
• Click the Edit button.
• Now add your account and give it Full Control
• Click Ok
• Click Yes at the "Windows Security"-prompt
• At the "Error Applying Security"-prompt click Continue once and Cancel at the next
• Click Ok at the "Windows Security"-prompt

You can now copy files/folder into this directory.

To get control over all the other directories you could "Get Ownership" of this folder but that's not recommended. (you already have read access of those)