Error 1721: There is a problem with this Windows Installer Package

[Xpert]

SYMPTOMS

While attempting to install Java, a message box with the following error appears: Error 1721. There is a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support or package vendor.

CAUSE

We are still investigating the root cause of this issue. SOLUTION

1. Disable/Configure any anti-spyware or anti-virus software on your system during installation process. For example: Spybot Search and Destroy Program or Norton Anti-Virus
   
2. Check to see if any spyware or adware is installed on your system blocking the completion of install process. For detailed instructions, visit:
   Adware_Spyware faq
   
3. Check to see if you find any unwanted entry in Add/Remove Programs or Internet Explorer - Add/On's section (Tools - Internet Options - Programs -> Manage Add On's). If you found one, remove/disable this entry.
   
4. On Windows Vista, disable UAC (User Access Control) feature for your account and download/reinstall Java again from:
   Windows Offline Java Download
   

Steps to disable UAC (For Vista Users):

1. Click Start, and then click Control Panel.
   
2. In Control Panel, click User Accounts.
   
3. In the User Accounts window, click User Accounts.
   
4. In the User Accounts tasks window, click Turn User Account Control on or off.
   
5. If UAC is currently configured in Admin Approval Mode, the User Account Control message appears. Click Continue.
   
6. Clear the Use User Account Control (UAC) to help protect your computer check box, and then click OK.
   
7. Click Restart Now to apply the change right away, or click Restart Later and close the User Accounts tasks window.