Ok, It seems the file you download from VMware site is corrupted by any reason. So you have two options:
1. you can go to vco server home page (I think in 4.2.2 it is http://orchestrator_ip) and use java web start client by clicking Start Orchestrator Client link
2. go to vco server home page (if it is not http://orchestrator_ip/ you can go there by clicking the link in Start menu/VMware) and press Download vCenter Orchestrator Client Installable and download the 32-bit client exe - it should work
Hope this helps,
Galina