I reinstalled Windows on a computer that had previously been infected with malware. Before signing in to the Microsoft Store again, I noticed that my old download or app history was still visible in the Library. Does this information come from the computer or from my Microsoft account? Could its presence mean the malware survived the reinstall? I may give the computer to someone else later, so I also want to know how to remove my personal data completely, including any data associated with Steam.
3 Answers
For giving the computer away, sign out of Microsoft, Steam, browsers, cloud storage, and any other services first. Then securely erase the old system drive or delete all partitions during a clean installation. Steam works similarly in that game and purchase history is associated with the account, so a new owner using their own account should not see yours, provided you have removed your account and local files.
The important detail is how Windows was reinstalled. A reset or refresh may leave some files and settings behind. For the strongest cleanup, boot from Windows installation media, delete every partition on the system drive, and perform a clean installation. Afterward, use a local account if you are preparing the machine for someone else, rather than connecting your own online accounts.
The Store library is generally tied to your Microsoft account rather than stored as a complete history on the computer. Windows can also show built-in or previously installed app information before you sign in fully. Seeing that list does not by itself indicate that malware survived.

I wasn’t signed in to any account after reinstalling, which is why the old information worried me.