I have checked the documentation for Vix 1.8.1

Following remark is mentioned in the Release notes.

• VIX 1.8.1 is the standalone VIX API release that incorporates compatibility libraries for Workstation 7.0 and Player 3.0. It also includes earlier VIX libraries delivered for Workstation 6.x and vSphere 4, without changes to those libraries.

As specified above, no changes have been done to workstation 6.x and vSphere 4 libraries. This is just a standalone release for Workstation 7.0 and player 3.0.

Also, a remark is mentioned that a new api i.e. VixHost_OpenVM has been added. So, in vix 1.8.1, this api is available through Workstation-7.0.0/32bit/vix.lib file.

From your post, I see that you are linking your program with VSphere-4.0/32bit/vix.lib. It doesn't contain the bits for VixHost_OpenVM() api. If you are developing an application for VSphere, i suggest you download the latest VIX 1.10 beta.

-Thanks

Sankar.