Are you installing to the default location?
Internet search found this might be helpful for you on 1720 error:
1) Your computer may have an outdated or corrupt version of Microsoft Windows Script. Please download the Microsoft Windows Script containing Visual Basic Script Edition (VBScript) Version 5.6 from Microsoft
If you are running Windows 2000 or XP, click the link, Download details: Windows Script 5.6 for Windows XP and Windows 2000