I am planning to get rid of the SHA1 certificate signing algorithm in our certificates and switch over to SHA-256. Problem is, that Windows XP (before SP3) is not supporting this. Therefore I need to know how many people are still using these versions. Is there a way to seperate Windows XP SP1 and SP2 from SP3? I know that SP2 brought the "SV1" (Security Version 1) token to it's version string, but what about SP1 and SP3? Is there a way to distinguish these versions?