Why do I get script errors on one machine but not another?

This usually occurs with new methods or functions, such as FileSystemObject, try{} or With. The cause is that you have a script library that is older than the documentation or sample code you are working from. Here are the errors you might receive: 
 

Microsoft VBScript compilation error '800a03ea'  Syntax error     or    Microsoft VBScript runtime error '800a0030'  Error in loading DLL    or    Microsoft VBScript compilation error '800401f9'  Error in the DLL    or    Microsoft VBScript runtime error '800a01b6'  Object doesn't support this property or method: '<method or property>'    or    Microsoft VBScript compilation error '800a0400'  Expected statement

 
Keep in mind that there is always the outside chance that you misspelled the property/method, or are using a component where that property or method is in fact not supported. 
 
If you are running Windows 2000 or better, then it is almost certain you are either misspelling the method/property, or using a method/property that doesn't exist in the component you are accessing. An exception might be new methods introduced in the 5.5 or 6.0 scripting engines, such as JScript's new push method for arrays. 
 
If you are getting this error when using a MetaData type library tag for MDAC, make sure you are specifying a valid version and that you have the latest version of MDAC installed (get the latest from MDAC Download Page). 
 
For information on comparing versions between machines, see Article #2133. 
 
For information on when features were introduced, see these charts for VBScript and JScript (ECMA / non-ECMA). 
 
To upgrade the scripting engines on a machine, see Microsoft Script Downloads. 
 
For information on keeping your server up to date, see Article #2151.