A further to your enquiry, it is possible to call 16bit dlls from a 32 bit environement but is quite complicated and involves putting a 'thunking' code layer between vb5 and the dlls. The code will work but I wouldn't recomend it due to the fact that the latest version of WinCMES is now 32bit and features have been added to allow better access to the measurement interface from vb. If you are interested in upgrading I am currently working on encapsulating the dll interface into a vb5 class that can be used as an object a lot more easily than the current methods.