Upgrading from VCenter 4.1 to VCenter 5.5

Hi,

Hoping I am in the correct location in the forum.  I currently have Vcenter 4.1 and ESXi 4.1 hosts and

getting ready to upgrade to VCenter 5.5

My VCenter 4.1 is on Win2K8 R2 server but is standalone.  I also have a working Active Directory

infrastructure and the question is:

a. Do I need to add this standalone Win2K8 R2 server to ActiveDirectory before running the

    VCenter 5.5 upgrade?

b. Is being a member of the domain a requirement for VCenter 5.5?

Thanks in advance,

VM3434