Unable to install itunes on my pc

Hi friends,

I was using iTunes for many weeks until it suddenly stopped working and giving me an error.  

I uninstalled it and download a newer version, and when I tried to install it on my windows machine, it shows me the error. The error says,

Windows Installer. This installation package cannot be installed by the Windows Installer service. You must install a Windows service pack that contains a newer version of the Windows Installer service.

A screen shot of the error is given below:

Windows Installer

This installation package cannot be installed by the Windows Installer service.

You must install a Windows service pack that contains a newer version of the Windows Installer service.

OK

I would like to install and use it, as I am a music geek and always fond of new arrivals on iTunes. You can say that my life is nothing without it.

Now I am seriously thinking about shifting to Mac but till then, I need my iTunes back so please help me.

Thanks.