Bitdefender Ts 2009

Hi, I am trying to install Bitdefender Total Security 2009 on my Laptop but this message comes up when the installation starts (I get through which folder the files etc shold go in).

Error reading from file C:\Program Files\Common Files\Bitdefender\Setup Information\{C731ACA8-EEE2-4B5A-9838-41D0AAD080C8}\bdts.msi. Verify that the file exists and that you can access it.

If anyone can help this would be vry much appreciated as I cannot afford another AV program!

Thanks in advance

Ross