Pardon if this is a stupid question, but...

[daemonmf]

If I use a copy of a full version of Vista to upgrade to Win7, will that nullify my CD key for Vista? i.e. say i want to go back to Vista later or dual boot.

 

[gimp]

it depends on what Win7 license is used.
Is it a Win7 upgrade license? If so, then legally you cannot reinstall Vista on any machine (if Win7 is still installed), as that is against the EULA.

 

[jeremyshaw]

EDIT: Ignore this.

 

[Arainach]

You certainly can't dual-boot Win7 and the copy of Vista you used to upgrade to Win7. If you uninstall Win7, however, you can re-install Vista.

 

[daemonmf]

Specifically, the win7 is the $30 upgrade being offered to students. I'd be installing Vista back on the same computer.

 

[Mjg1675]

it depends on what Win7 license is used.
Is it a Win7 upgrade license? If so, then legally you cannot reinstall Vista on any machine (if Win7 is still installed), as that is against the EULA.

You certainly can't dual-boot Win7 and the copy of Vista you used to upgrade to Win7. If you uninstall Win7, however, you can re-install Vista.

This and this.

 

[bigdogchris]

If I use a copy of a full version of Vista to upgrade to Win7, will that nullify my CD key for Vista? i.e. say i want to go back to Vista later or dual boot.

Yes, it will. Technically there is nothing stopping you from using it again but it will be an illegal version in Microsofts eyes. You can however reinstall Vista at a later time as long as you delete the 'upgrade' system that now has 7 on it.

 

[Catweazle]

Using a Windows 7 Upgrade pack will render your Vista license 'void' in a legal sense. Your Vista key will NOT become blacklisted and unusable, but if you continue to use it or use it again later you would be operating in a legally unlicensed fashion. You are allowed to use it afterwards only to reinstall your system and put a 'qualifying install' in place for the windows 7 installer to see.