hey tagwyn, have you either a copyprotection or a antivirus scanner problem...??
In case of the scanner, simply deactivate both scanner and firewall and then try the installation.
In the other case simply get another drive from a friend and try then the installation.
I got such similar messages sometimes with other programs I like to install.
Because of that I deleted my until then beloved Zonealarm-Firewall on my Laptop because of strange behaviour.
But it could be even another problem, but I think that Philippe can help you...
greetings
Hohenlohe
edit: please check if some of your installed games are using either Securom
or Starforce DRM, in the first case you will get very strange behaviour accessing your CD/DVD-Drive as I know especially if you are using drm-free Games-CDs, as this prog usually check for DRMs...
R.I.P. Henry D.
In Remembrance of my Granduncle Hans Weber, a Hungaro-German Soldier,served in Austro-Hungarian Forces during WWI,war prisoner, missed in Sibiria 1918...