Often videos from tablets and iPads can output the wrong way when imported to a PC. This is commonly caused by the way the tablet or iPad was held during recording of the video.
Videos are played within a program called 'VLC'. Open the video which is currently the wrong way up and follow the steps below.
1. Go to 'Tools' > 'Effects and Filters'.
2. on the 'Adjustments and Effects' dialog box, select the 'Video Effects' tab.
3. Then select the 'Geometry' tab.
4. Check 'Transform' here.
5. The drop down menu below 'Transform' can now be set to the orientation you wish the video to be displayed in VLC.
Select the orientation you wish the video to be played.