My phone is so basic that it hasn't even got a camera, so this isn't my area of expertise, but I suspect that your phone's memory might now show as a new drive in 'My Computer'.
Double-click on 'My Computer' to see which drives are shown. If you can see your phone, double-click on its icon. You'll either see your image files, or a folder containing them. (If so, double-click on the folder icon. If you see another folder icon, double-click on that one as well).
If the window you're viewing takes up all, or most, of your screen, make it smaller. (Click the overlapping rectangles symbol, next to the 'close' button, at the top right of the window and/or drag the edges of the window). Then go to 'My Pictures' (or wherever else you want to save your pictures). Resize that window, so that you've now go two windows alongside each other. In the 'phone' window, go to Edit>Select All, to highlight all of your image files. Click on any of them and, while holding the mouse button down, drag the files across to the other window.
Chris