Windows 7: Update W7 RC

I understand, that I can not do upgrade Windows 7 7100 to other build without reinstaling all now working programs...

I've had NO problems with upgrades. In fact, I've done a couple via Remote Desktop, and never needed to touch the physical machine at all. I don't understand why everyone does a fresh installation each time, unless it's for testing purposes.

Upgrade is always risky - many posts here - I mean you have updated 7100, changed for sure some drivers or configs, and new built will install another, so ssome applications may not work properly and it is sometimes difficult to find out what is wrong. As you probably know it is easy to waste few night and finally - to reinstall everything is the only solution. Or at least optimal.
best regards,

In some cases just for testing, in some other as working system. In my, it is the only working system (limited space) so I make testing and changes rather carefully. The main purpose for me is to get knowledge about this new system before I buy it. And thanks to this forum and many smart persons (my best regards) I can learn a lot and very fast.

You can still try upgrading as I said, but like others have said it may cause driver or other issues that we don't know about , as you know these builds are still under testing and they may have bugs still, so clean install is safer but doesn't mean you cannot upgrade, you can try and see if it works, if not try a clean install

OK, I will same wait with 7100RC and after to do clean install. Thanks