activations with XP Retail versions

A question concerning activations in general, but am I right that with the retail version, there is no limit as to how many times a person can activate XP on the same PC that is used?

Suppose in a situation, you install XP and everything goes well, you activate it, and for some reason or another, somewhere along the line something happens and you are forced to to do a reinstall, for example, after you activated, a few days later, something happened that you have to reformat and reinstall again, thus having to reactivate, that shouldn't cause any activation issues being ont he same hardware.

Has anyone here been through that situation or something similar?

As far as I know with Retail, I don't think there is a limit to how many times one can reinstall/activate on the same pc that is being used?? (One PC at a time)