Hi!
Which codec exactly do you want to buy?
Regarding the Microsoft Store issue, it could be a problem specific to the Store or a general one. Do you use other Microsoft apps, such as Office, 365, Clipchamp, or OneDrive? If so, do they work normally?
Windows Update might also be having issues, so check if it is installing updates as it should:
- Open System Configuration > Click ''Windows Update'' > ''Check for updates''.
- Download all available updates. Click ''Advanced Options'' > ''Optional Updates'' > Select all available drivers and updates > Click ''Download and Install''.