A clean install is required, you can use the W7 Easy Transfer Wizard to save your files and settings to another drive/cd/dvd, however you will need to reinstall your programs.
It's not recommended you try to upgrade from the W7 RC.
could i switch everything to another hdd and then reconnect it after the fresh install and then switch what i needed to back onto the primary hdd ? i see was suggested already , can this be done with another sata drive -- labeled as storage then reconnected after fresh install ?
As I stated you can save your files to another drive, a second internal or external usb/sata/firewire drive using the W7 ETW.
"could i switch everything to another hdd and then reconnect it after the fresh install and then switch what i needed to back onto the primary hdd ?"
NO! You CAN NOT move the programs from one drive to another and back again.
Use the second drive to store the backup file made by W7 ETW, then restore it back after you have completed the upgrade.
was very easy and straight up ..
fyi , once I added the ETW back to new install , all my settings and programs worked as before ..
what i did tho was after the ETW , i disconnected the drive and formatted the main drive ( is a Raptor) for clean install , once win7 was on and working ( matter of a few minutes) I reconnected my storage drive and ETW everything back to main drive as the new comp .