New Windows 7 x64 PC unable to auto-install / push install / upgrade SEP 12.1 RU1 MP1

Hi All,

I cannot do the push installation and also auto upgrade of SEP client v 12.1 RU1 MP1 into the Workstation which has been installed as Windows XP 32 bit and now re-installed with Windows 7 x64 SP1.

from the SEPM server the ping doesn't reply back but the PC is now online, the previous entry in SEPM is still there same name and IP address but appears as offline (due to no SEP client at all) ?