Windows 7: Anytime Upgrade

Hi. Thinking about upgrading a pre-installed windows 7 home to Windows 7 professional using the anytime upgrade option. Just wondering if doing it this way do i need to backup everything of importance first? I reckon most will say to do this as a precaution, and i probably will but is it necessary.

Its not necessary, but its always a good idea...

Thanks Tews.
Main reason to upgrade is to enable me to backup a already loaded pro laptop to this PC over a network, which i believe is only possible with both having pro or ultimate loaded on both machines? I am also abit fed up with the price here in UK of the upgrade £120! You have it alot cheaper in the states, that so sucks

That's why I have a TechNet subscription ...

Anytime upgrade only adds-on the Programs & Features from version to version.
Windows Anytime Upgrade - How to

I know, thats the reason i need to preform a upgrade to win 7 pro, so i can backup a laptop to PC over a network to a remote HDD.

I am also presuming if i purchased a key from a retail shop, i would be able to enter this in the anytime upgrade option and it would preform the same as if i purchased the key from MS through the anytime upgrade option?

there is no need of back-up. All the installed files will remain as it is.

anyone here needs any time update key of Windows 7 pro..????

Yeah....till the odd ball chance it freezes up on moving your settings....then you have two unbootable window installs....