Hi @Azar,
Welcome to Microsoft Q&A forum.
It sounds like you are stuck in a classic administrative "deadlock." It is quite common for devices used during college to have permissions tied to an old institutional account, leaving your current personal profile as a standard user without the authority to install apps or reset system settings.
Since User Account Control (UAC) is doing its job by blocking changes, we have to bypass the active Windows environment entirely to regain control. Here are some effective ways to handle this:
Method 1/ Reset from Windows Recovery Environment (WinRE)
Hold the Shift key while clicking Restart from the Windows sign-in screen (bottom right corner). This triggers the Recovery Environment. Then go to Troubleshoot > Reset this PC > Remove everything. This can allow you to reset the device even if you can’t sign in normally.
Important: If the drive is encrypted, you may be prompted for the BitLocker recovery key during the reset process. If you don’t have that key, you may not be able to continue with certain reset options.
Method 2 / Reinstall Windows using official installation media
This is a reliable way to reinstall Windows and start with a fresh system state. You’ll need access to a working PC and a blank USB flash drive (at least 8 GB). Create installation media using Microsoft’s official Windows 11 download page (“Create Windows 11 Installation Media”).
Important: Reinstalling Windows using installation media can erase existing apps, settings, and personal files, so back up anything important first (for example, to an external drive or OneDrive).
If the device is managed by a school or organization, reinstalling Windows may not remove organizational management—during setup, a device can download a management profile and automatically enroll again once it has network access. In that case, the correct path is to contact the school/IT admin to remove the device from their management before it can be set up for personal use.
After reinstalling, Windows typically activates automatically once you’re online. (If major hardware was changed, reactivation may be required.)
I hope this helps you get back to your university work quickly. Best of luck with your studies!