This is something that trips up new users of InstallShield. In particular, those who are writing a script using the InstallScript language.
InstallScript is very C-like. That’s why it’s easy for C, C++ and C# programmers to learn it. However, there is one glaring exception that gives people some trouble.
Here is a code snippet from an InstallScript MSI installation:
The Logical Equals Sign in an If Statement
Notice the comparison in the If statement I have circled. It uses a single = sign. Not a double one like the logical equals in C.
When you need to form a logical equals, remember to use only one equals sign.