I have just received an old HP Compaq 6715b laptop. It has no harddrive so I will need to add one. Any ideas what hard drive I should put in this (size etc)? I will probably install ubuntu on it and use it for browsing etc though I'm still not 100% what to use it for. Could you use it as a media server or something? What about SSD harddrives - do they only work on windows 7? I'm looking for something cheap - less than 80GB would suffice. Thanks for any recommendations!