Failed to instantiate script engine 'VBScript': Invalid class string

[mcguirk000]

I get this error every time I try to run a VBScript step on a particular machine.

I have the VBPro project running on several other machines with no issues, but on this one machine I get the above error.

It is a Windows 7 x64 machine running VBPro 7.6.

Even if I create a new project that does nothing but execute a single VBScript with nothing but comments in it, I get the error.

Any ideas?