Are you logged into an account with Administrator privileges with the right to install software on this PC?

Did you disable your antiviral software (eg, Norton) before you tried to install iTunes? Don't forget to reenable the antiviral software afterwards, :emotion-5:

You might try changing the compatibility mode for the installation package to Vista (or Win XP if you have Win 7 Ultimate). 

Ron

I tried all your suggestions and still got the same error message. I could only change the compatability to Windows Vista (service pack 1 and 2)  or Windows Server. None of them worked.

Thanks!

I have it installed on my Win 7 PC, it's not a "Windows" problem as Apple suggests.  

Run system restore back to a date PRIOR to first attempting to install iTunes.  Download a new copy of ITunes and try the install.  The system restore will give you a "clean start" to try and install.   System Restore can be accessed by Start/Programs/Accessories/System Tools.  System Restore will not delete any user data or e-mails, but any programs or progam updates installed after the restore date will have to be reinstalled. 

FWIW, iTunes seems to be a problem (various problems) on a lot of PC's.

I also have it on my 7x64 laptop with zero problems.  Did you download the package from apple.com ON the computer you are trying to install it on?  If not, I would recommend going to apple.com from your 545 to download it, where Apple will normally choose the best download for your system.  iTunes has an x64 version that it will automatically give you if accessing the download from a machine with a 64-bit OS.  This download will NOT work on a machine NOT running x64 (and the 32-bit installer will not work on x64 OS) and will give you a similar message.

I did download it directly from apple.co and it was the x64 version.

I also have it on my 7x64 laptop with zero problems.  Did you download the package from apple.com ON the computer you are trying to install it on?  If not, I would recommend going to apple.com from your 545 to download it, where Apple will normally choose the best download for your system.  iTunes has an x64 version that it will automatically give you if accessing the download from a machine with a 64-bit OS.  This download will NOT work on a machine NOT running x64 (and the 32-bit installer will not work on x64 OS) and will give you a similar message.