I bought a Raspberry Pi Starter kit online (and it came with a sd card), and had it running Raspbian. I then went and installed Rasbmc on it and I corrupted my SD Card. I wiped it clear and then installed Noobs on it and ran Rasbmc. I wanted to go back and install Raspbian on it again but it said I did not have enough memory. I wiped it AGAIN and installed noobs, plugged it into my raspberry pi and it said I did not have enough memory still. Since then, I have tried formatting it several times but I cannot get it to clear. I am trying to do this from a Mac.
I cannot comment so I'll have to post this as an answer. What size is your SD card? Somewhere I read that the latest versions of Raspbian require 4GB+. I have found that NOOBS often requires a bigger size because it has an installer and then also has the operating system you want to use (Raspbian, OpenELEC, RaspBMC etc etc).
NOOBS require atleast of 4GB memory. So we need atleast 8GB memory card for it's installation. I think you got 4GB SD Card. That's why it shows it doesn't have enough memory to carried out installation.