I recently bought my external hard drive enclosure the RetailPlus EU20 2.5" SATA HDD Portable Enclosure, after my hard drive on my macbook crashed. (Late 2008 aluminum 13" macbook). I brought it into the genius bar for repair, and they ended up giving me a new hard drive because my old one wasn't working. Now, after buying the enclosure and putting my old hard drive inside it, my computer doesn't recognize the hard drive enclosure at all. Not even on other computers (Toshiba satellite). The hard drive works in the enclosure, the light flashes and I hear it running, and I also hear the clicking noise that made me bring it into apple. I was just wondering if this would be a problem with the Enclosure itself, or if it's a hard drive problem (making all this effort a waste and all the files I had on my old hard drive lost). I really appreciate everyone's help! Thanks in advance for posting!