rct3 install problems?

every time i try to install rct3 on my system it gets to about 70% done and says invalid transfer error.
has any one else had this problem or does any one know how to fix it, and befor you ask my system is up to scratch with all the requirements of rct3.
im stumped?
can any one help please?

[coolbeans326]

^ i got that with the original Need For Speed:Underground, its just you computer. Maybe get some more memory for your computer, or maybe you just got a bad disk.