If photoshop doesn't work well for the time being, it is recommended to use the picture viewing software ACDSee (the one with big eyes) to compress the pictures, which may be available on your machine.
Your picture can only be reduced by changing the size and format.
Open the software first, click Open on the menu, browse to find the picture, click Edit, click Resize, enter the desired size in the new size dialog box (note that the aspect ratio remains unchanged at this time), click OK, click File, click Save As, note that the file type selected at this time is jpg format, and finally click Save.
If you want the picture to be as large as possible, you can choose gif as the format.