To that what cdkiller says......
For older games it is true that some files get copied to another place then the install folder..... but the registery entries doesent matter ! I copyed a lot of games that way cause i hate to destroy my RW´s by trying a dozen times to get a working copy of a game for example Gothic 2 if u try to make a backup copy of it ,it will check the 3´d cd before install is complete if a copyed cd or wrong cd is detected the installation gets deleted
And a lot of games dont let u install with a copy ,or the cd is not working correct.....
And if u make it that way i told u before u safe discs Example Splinter Cell ( normaly 3 CD´s ) own Setup ( 2 CD´s )
And sure u have to save the original exe files as well for updates!
Forget to say that in my message before
Sry if my English is not very good to understand but i think u will get the idea of it .........