Before I can answer you, how did you go about the steps?
1. Did you download the mediacreator and create a USB install or a DVD install?
2. Did you try the install while Windows was running? Meaning you just put in the USB or DVD and started the install?
3. Is this machine a custom build or an OEM (i.e. Dell, HP, Lenovo) machine?
4. Did Windows 7 come pre-installed on this machine or was it a retail copy that was used to do the install?