Well I think the time has come to get my feet wet with unbutu.This will be desk top No server. 1.Question.When I download the ISO to a CD/DVD Should I select standard pc.My pc has the requirement for 64 bit but currently has 32 bit vista HP factory OEM OS. 2.Question.When Running The CD/DVD I will have the option of Testing am I correct.Not Really sure If I want it as my primary OS and Do not plan for VMware or partioning at this Time. 3.Question. Will Ubuntu work From A extrenal Hard Drive if I used that to run it. 4.If I choose to install to my Main OS,No more windows,Should I Download the ISO 64 Bit instead. 5.The pros and cons and any recomendations. Nieve to linux based so please bear with me. Thanks In Advance My specs HP laptopVista HP-SP1. Intel duo 2 cores, 1.7 g, 3 gs Ram, 250 HD-space,Intel 965 chipset.