error messages

Hi wonder if anybody could help, For no apparent reason i got an error mesage when i tried to run the game and i forgot to record the error Number. anyway i put disc 1 in and tried the repair facility but then again had an error message which i didnt take down yet again, i then used disc one to unistall the game , now when i have come to reinstall it, it goes through disc 1 and all the way into disc 2 to the end but then get error 1722 and then another error 1603. wonder if anybody could help .. thanks