I noticed on another thread that you were using my transfers. You do NOT need to flip/rotate the design for my transfers.
Just in case you are also using other transfers as well: You can flip or rotate the design in a few different ways. I know in Paint (which most/all computers have, under Accessories) you can open your design and then under the Image tab, you will find Flip/Rotate. Others have also said that the option is often in the print menu. I do also know that most printers are 'smart' and if you choose iron on transfer paper as your paper, it will automatically flip the design.
So be sure to NOT to choose iron on transfer paper when printing to my paper.
I hope this helps!