How do I install Interstate 76 on Windows 2000, Windows XP or Windows Vista?
Go to Start, then Run, then type d:\setup.exe -lgntforce, where d:\ is your CDrom/DVDrom drive. (note: that's -lgntforce, lowercase "L". If you're unsure, copy and paste it from here.) This problem arises because Win2K, WinXP and Vista are based on the NT kernel, which had DirectX support which was flaky at best. Thief needs DirectX to run, so, when the installer sees the NT kernel, it assumes that the game isn't going to be able to run and quits the installation. The -lgntforce switch tells the installer to ignore the NT kernel and install anyway.