post your current computer. easiest way is to download speccy and post a screen shot of your computer

http://speccy.piriform.com/results/5N4qKbM3a24qr8PhViiBWCu

its my friend computer btw , im try to help him

Can re-use the hdd, that's about it. Extremely low budget for what you're wanting it to do.

Seriously.. I wouldn't even waste the time to save the hard drive. Throw that thing in the ocean and spend a grand on a new computer. Especially if he wants to stream.

vouch, or at least $650-700 is the lowest you can do that will meet those requirements.