If i install windows 7 beta and after the trial ends will i still be able to have vista? (i dont have the disc? -

no, you would be screwed over. You can run both if you want? Ill set you up a tutorial buddy. http://lifehacker.com/5126781/how-to-dua...

if you dont have the disk then you can t go back to vista unless you buy the vista disc if you dont want to buy the disk run windows 7 as a virtual machine then you dont have to format your hdd and you can keep vista and if your not a beta tester and have never tested a beta and you dont know much about computers i dont recommend using the beta

you need the disk to reinstall vista