Won't play downloaded movies

Maybe your player is not compatible with the video format that you played. You can try some other player programs for your computer. Here are some of the free player recommendations for your reference:
1. Leawo Blu-ray Player
This player is a free 4K and Blu-ray player which can support most video and audio formats.
2.UM Player
As a free multimedia player, it builds in over 270 video and audio codecs so you can handle nearly all media formats, including DVD, AAC, AC3, ASF, AVI, DIVX, FLV, H.263, Matroska, MOV, MP3, MP4, MPEG, OGG, QT, RealMedia, VOB, Vorbis, WAV, WMA, WMV, XVID and many more. This unique free DVD player software also has unique features such as subtitles search, skinable interface, customizable hotkeys and a lot more. UM Player also reads damaged media files and scratched CD/DVD.
3. GOM Player
Not only DVD, it could play files in formats such as AVI, DAT, MPEG, DivX, XviD, WMV, ASF. It's also capable of playing even the damaged video files by skipping the frames.

What's the movies' format? If the format can't be supported by iPad 2, you should convert it to MPEG-4. You can find solutions on iFunia iPad column.

Have you tred upgrading the software it uses