As long as you have the 32 bit version of Vista, click on Start, then type "Run" in the Search line, then type the command below in the "Run" line:
Press the "Enter" key.
As long as there are no error messages, it's now registered. (Full instructions for running such from a command line in both 32 and 64 bit versions is in the link below:
Hope this helps.
Is there a way to tell if the jscript.dll is registered in my machine's registry?
What would I notice if it were NOT registered?