Hi, my mid 2009 mac book pro's harddrive died. I bought a western digital hard drive off of amazon and installed it. I attempted to back it up from time machine but it failed multipe times so i decdied that I would just do a clean install and start from scratch. After in the install took 12 hours it finally finished. Now I have all the updates installed and it is running slower than I have ever seen! I get the pinwheel all the time. I have reset the permissions and that had no effect. I have run the hardware test and that came back clean. I will try anything please let me know what you think, thanks.