i want to install beta, of windows 7. if i use backup and restore in vista, will i be able to get my vista os back if i saved with this method?

In theory, a Complete PC backup should, but make certain that you have your original Vista install DVD to access the Windows Recovery Environment. No telling if the Win 7 equivalent is compatible with a Complete PC image made from Vista. You can always test this and let us know.

Would the Dell Device Drivers serve as a tool for that? to install vista?

Dell device driver CD, you meant? Dell device driver Cd only contains the device drivers, and is only needed if you do a clean format and installation of Windows.If you use Complete PC Backup to backup your entire Vista system, all files, device drivers, and program files will be backed up.To restore, just use your Windows Vista CD and boot into WinRE, and do a restoration from there. When your computer boots up, it will look just like when you backup your system. Jabez Gan [MVP] - http://www.msblog.org

It seems you bought a PC that came with Vista pre-installed... without a Vista install CD, it will be risky to install W7 over Vista.Be sure to back up all your important data to an external device before you proceed installing W7.

If this is an OEM Vista system without restore disks, then you may have to create the restore disks on your own (that's what most manufacturer's do these days). Also, if there's a recovery partition on the drive (for the Vista installation) you'll have to preserve that. Some systems require that you boot from the recovery disk to access the partition - while others will let you boot straight to the recovery partition to restore Vista.This does not backup any of your files or settings - so the use of the Files and Settings Transfer tool or the Complete PC Backup tool will be necessary to save your files. - John

To see the complete PC process have a look at this screen cast that Keith Combs did on Technet Edgealso have a look at this article fromTechnet Magazine on vista backup technologies.RegardsGordonwww.longneckconsulting.com