Saving YouTube Videos

Hi everyone,
I found out how to save youtube videos but the saved version opens up in only a tiny window. Does anyone know how to save them in an expanded format for easier viewing? Zooming in on the video window doesn't work, it only changes the resolution and makes it blurry. Thanks for any help.

Re : Saving YouTube Videos

I don't know what the answer is but maybe if you search the youtube help section that might give the answer