My PC ran a suspicious PowerShell command and Steam stopped working—what should I do?

The Steam errors may be a side effect of replaced or modified executables rather than a simple Steam problem. Contact Steam Support from a clean device to secure the account, revoke unfamiliar sessions or API access if available, and check for unauthorized purchases. Avoid trying random cleanup tools on the compromised installation.

That command downloads and runs an external PowerShell script, so you should treat the entire system as untrusted. Back up only personal documents, photos, and other files you’re certain are safe, then completely wipe the drive and reinstall Windows from official installation media. A normal reset that keeps files may not be enough.

Upgrading from Windows 10 to Windows 11 probably won’t solve this by itself. An upgrade preserves much of the existing installation, while a clean installation removes the compromised system files and programs. After reinstalling, update Windows, reinstall applications from official sources, and scan any backed-up files before restoring them.

Assume the computer has malware or even remote-access software installed. From a different, trusted device, change your important passwords—especially email, gaming, banking, and password-manager accounts—and enable two-factor authentication. Don’t use the affected PC for sensitive logins.