Formatted sd card now space is alot smaller...

I used this software called memorytest86 to test my memory

Instead of using a cd i decided to just quickly use the usb option.
I used the program it came with to format the sd card.

HOWEVER after it was formatted it shows that i only have like 50 mb of storage.

I had 8 gb on this how can i revert back?

 

I've never formatted an sd card so I can't say if this is good or bad.
http://www.online-tech-tips.com/free-software-downloads/formatting-sd-card/
and the download for windows is here https://www.sdcard.org/downloads/formatter_4/eula_windows/

 

I was actually already trying this software a bit before and had not results other than '' cannot format this card'' error.

After like 3 or 4 times the computer said my sd card was corrupted. At which point i inserted it into another computer and it read the whole 7.4 gb however it stated it needed to be formatted so i used the software again and it seems to be back like it was.

Steering a bit off topic the memorytest86 app is fairly accurate? At least judging from posts in this board it seems some people rely on it its results to test memory and rule out some things.