Help me work with pictures PLEASE!!!!!

[EKM Yu-gi-oh]

I need help because...I was all happy donwnloading pics for cool cards and when I started uploading some of them(some of the coolest!!)werent accepted because it said they werent pictures! so the question is...

 

Can someone tell me how to change the pics format from PNG(and maibe any other that is unusefull)to like JPEG or one that its accepted?If there is a way plz help me!

 

Thanks in advance to anyone that helps!

[Enma Ai]

when you are uploading a picture just edit the name of it.

change the .png into a .jpg instead

[EKM Yu-gi-oh]

I just tried that but when I change it on the uploading screen it acts as if it was looking for a picture that does not exist and so it does not works...also I tried changing the type (PNG)of the pic to jpg using notepad but all that does is brake the pic and it dont work again even if I change it back!.What a bother someone plz help!!!