I am getting the message "The windows installer Service could not be accessed when trying to install Itunes on my new computer, any help would be appreciated.

Hey there Frank0619,

If you have not been able to install iTunes because the Windows Installer service is not available, I would recommend the troubleshooting in the following troubleshooting to help.

Issues installing iTunes for Windows

These in particular:

1. Make sure you have an administrator account.
   To install iTunes, you'll need to log in to your computer with an administrator password. If you're not sure if you have an administrator account, read Windows 7: How do I log on as an administrator? You could also refer to your computer's help system, contact your IT department, or visit support.microsoft.com for assistance.
   
2. Install the latest Microsoft Windows updates.
   To download the latest updates, visit the Microsoft Windows Update website. iTunes for Windows requires Windows XP, Windows Vista, Windows 7, or Windows 8 with the latest Service Pack installed. If you can’t install the updates, refer to your computer's help system, contact your IT department, or visit support.microsoft.com for assistance.
   
3. Download the latest version of iTunes.
   The latest version of iTunes can be downloaded at http://www.apple.com/itunes/download/.
4. Disable conflicting software.
   Some Windows background processes can cause issues for other programs and processes. These conflicts can prevent applications, such as iTunes, from installing. Disable conflicting processes by starting your computer using MSConfig:
   • Using Msconfig to troubleshoot conflicts in Windows XP
   • Using Msconfig to troubleshoot conflicts in Windows Vista, Windows 7, and Windows 8
   Some security software made by other companies can't be disabled using MSConfig. If you've installed security software and you're having issues installing iTunes or QuickTime for Windows, you might need to disable or uninstall security software to resolve installation issues.
   
5. Restart your computer.
   
6. Install iTunes.

Thank you for using Apple Support Communities.

All the best,

Sterling