Upgrading from Vista Ultimate to Vista Ultimate SP1

would it work? would any files be corrupted or anything gone wrong? since I cant install SP1 or SP2 for my old vista, I'm upgrading to Vista with SP1 already configured with the OS. I'm wondering, instead of clean install, I prefer to do an upgrade, would it work? and what changes would it do? thanks

Why cant you install SP1 or SP2? Ofc it will work, it will just add the benefits of SP1

http://technet.microsoft.com/en-us/library/cc709618(WS.10).aspx see this for more on SP1.