I need help/advice. I've been trying to post new videos on my YouTube channel but it won't work.

The size of the video does not matter, and I've tried to post in different formats (WMV and MP4) and it still won't work.

It just stays for a whole day on "Uploading: 0%" and then it says the video had an error and could not be uploaded.

Has anyone else had this problem? Is there something I can do about it?