will vista require valadation of exsisitng operating system?

Hello , I have just built a new pc and have xp proffesional installed on it, from what i have read i can not do a standard upgrad (due to it being xp proffesional) but will need to do a fresh install, if i buy a upgrade version of home premuim i no it will give me the option of a fresh install, but will it make me confirm the validity of my current operating system by having to insert the orginal CD???

im sure thier are many people who through varied legitimate reasons do not have thier orginal CD, mine was damaged beyound repair, does this mean i will have to buy a full version of vist home premuim which is extremelly expensive!!!!!!!!

any help from vista experts would be most helpfull !!!!

i have read the offical microsoft site but of course they are vauge on details, may be the case of holding off on installing it for a few weeks and checking various forums to see feed back from other people, i would hate to spend all this cash on buying vista only to find i cant use it !!!!!!

well if the past has any say in it, windows has always asked only for the CD (or floppy) and not the actual key. so if you had a legit win XP upgrade, when it asked you for your proof of older windows you could throw in a (hypothetical) random illegitimate 98 or ME cd and it would go.

To install an upgrade version of Vista you will have to have installed a validated version of XP before hand. You won't need the CD unless you are planning another Vista install at a later date. If your XP CD is fubar'd because your dog ate it or whatever other excuse for not performing the simple task of putting it back in the case, and you cannot get a replacement from MS for whatever reason (i.e. you stole it in the first place), then you should get the full retail or OEM version.