How to save a screenshot as a photo?

[hey babes!]

Okay, i need to save a screenshot as a photo. if i use paint, it doesnt work as a photo and i cant upload it to facebook, twitter, photoshop ect. so can someone please tell me how to save a screenshot (like from youtube) into paint or another program so it saves as a photo.
and i have already tried going into "save as.." and then selecting the file type bitmap.
i dont know what else to do..please help?

[Ace]

I was just able to take a screenshot of Youtube and save as PNG, GIF, etc..Facebook or Twitter might not upload it because it's too big; I suppose you could just change the size after saving from the screenshot, then save again as the new sized image.

[Jay]

Try saving it and compressing as a JPEG

[Nahum]

In Paint, use "Save as" and choose PNG (Portable Network Graphics). You can also try JPEG, although Paint doesn't let you choose the image quality.

The "Bitmap" option saves an uncompressed file that won't be accepted by most websites. The only real reason to use it these days is for making image files to use as your personal desktop, or to save an image that you don't want altered by compression.