This happens because there is an error in the registry of the screenshot tool that comes with WIN7, so you can reset the registry. The specific operation steps are as follows:

1. Click "Win" and "r" on the keyboard to open the running window, enter "regedit" and click "OK";

2. Click "HKEY _ Current-User";

3. Click "Software";

4. Click on "Microsoft";

5. Click "Windows", then "CurrentVersion", and then click "Explorer";

6. Click "UserShell Folder", then double-click "My Pictures", enter "%USERPROFILE%\Pictures" in the numerical data window, and click "OK".