Why Does the MediCat Installer Close as Soon as I Open It

This is the number one cause. If you open the downloaded archive and double-click the installer inside the archive window, Windows runs it from a temporary location where the toolkit files are not present — the script finds nothing and exits instantly.

1. Close the archive window completely.
2. Right-click the downloaded archive → Extract All (or use 7-Zip → Extract to a folder). Extract to a simple location like the Desktop.
3. Open the extracted folder — you should see the installer file together with the other MediCat folders and files.
4. Run the installer from there. It can now read the files sitting next to it.

The installer formats a drive and writes a bootloader. A normal double-click does not give it those rights, so it can fail at the first command and close.

1. In the extracted folder, right-click the installer batch file.
2. Choose Run as administrator and approve the Windows prompt.
3. The window should now stay open and ask you for the USB drive letter — that prompt is the sign the script is actually running.

Windows quietly restricts files that arrived from the internet, and some folders fight back too:

1. Right-click the installer file → Properties. If you see an Unblock checkbox at the bottom of the General tab, tick it and click OK. (If there is no checkbox, the file is already unblocked — move on.)
2. Make sure the extracted folder is not inside a synced or protected location. Desktop or a plain folder like C:\Medicat works best; deep inside OneDrive folders the sync tool can lock files while the script is copying.
3. Keep the folder path simple — very long paths and special characters in folder names occasionally trip up batch scripts.

If the window still closes, something is stopping the script while it runs:

1. Pause real-time antivirus protection before running the installer, and only for the duration of the install. Antivirus programs frequently block or quarantine parts of repair toolkits (password and network tools are flagged by design of their detection rules), and a script whose files vanish mid-run just dies.
2. If Windows shows a blue "Windows protected your PC" SmartScreen box instead, click More info → Run anyway. This appears for many legitimate unsigned scripts; still, only do this for the installer you downloaded from the official MediCat website.
3. To see the actual error, open the folder, click in the File Explorer address bar, type cmd and press Enter, then drag the installer file into the black window and press Enter. Run from a console like this, the window cannot close — you can read exactly which line failed.