For playing Utube videos download Latest Flash player 11. click the following link
Download Flash PlayerClick here for download Flash player
When you download this flash player go to www.utube.com and play your videos. Now you can play all videos but you can't download these videos. If you want to download these videos, follow these steps.
1- Download Internet Download Manager (IDM) from following link
Download IDMClick here for download IDM
2- Now go to any website and play your video with you like, A DOWNLOAD button will appear on the website.
3- Click the Download button and give your path where you want to download it.
When your downloading will complete. You can play your video in later.