Exchange 2007 SP1 RU8 has been validated for HMC 4.0 and HMC 4.5
On a monthly basis, the HMC test team will conduct a Windows update compatibility test (where the major roll-ups and updates will be tested) on different versions of HMC environment.
Windows update compatibility tests (Exchange 2007 SP1 RU8 was included in this test) on HMC 4.0 as well as HMC 4.5 have completed successfully. This means Exchange 2007 SP1 RU8 has been validated for both HM 4.0 and HMC 4.5.