First try changing this setting in the BIOS setup Disable USB 3.0 functionality to install Windows 7 from a USB Flash Drive With regards to requesting the Reinstalaltion DVD which I recommend. For US customers there is an online request form for Reinstallation Media. For those customers not in the US you will need to contact Dell technical support and ask for one. The customer numbers are available here. Once you have the Reinstallation DVD follow my wiki A Clean Install of Windows 7. If you have troubles requesting the reinstallation DVD vote on the poll here.
Hello I created recovery media from Dell Datasafe Local Backup and saved it to a USB key. However my Dell Inspiron Laptop only has USB 3.0 ports so when I try to boot into the USB Key it tells me: "The system recovery image cannot be found. If you are trying to restore your pc from a USB 3.0 (blue) USB Port please connect it to a different USB Port, restart your PC and try Recovery again". If my laptop does not have the older USB 2 ports and apparently Windows 7 does not come with native USB 3 support then how can I re-install my system using this USB key I made from Dell Datasafe Local backup? I tried making a DVD set from Dell Datasafe but it failed I think there is a bug in the DVD recovery media routine of Datasafe  Local Backup. Am I better off requesting Dell to send me an OEM DVD re-installation set? How would I do that? Thanks.
Can't re-install Windows7 from USB key created with Dell Datasafe Local Backup