I do have a KMS client key but I do not understand how does that differ from windows ultimate?
All versions of Windows 7 require product activation. Starting with Windows Vista, for business users, Microsoft Volume Licence Keys (VLKs) have been replaced with Multiple Activation Keys (MAK) or Key Management Server (KMS) keys. MAK Activation may occur independently (by means of connection to Microsoft through internet or telephone activation) or through a proxy using Microsoft's Volume Activation Management Tool (VAMT). Hosts activated via a KMS have to report back to that key server once every 180 days.
Windows 7 Enterprise is a business OS and can only be activated with a Volume License MAK or KMS key if it is not activated against a local KMS server. Enterprise requires a VL KMS/MAK out of the box or activation against a local KMS server. It can be rearmed up to 3 times.
Windows 7 Ultimate Edition is a consumer OS and activates conventionally via the internet to Microsoft activation servers.
