How Do You Reformat A Modern Computer Without An OS CD?
If it is fairly new with Windows 7 starter it may have a built in recovery, if it does use that. If not then the only way is to order the system recovery disc from the manufacturer by model and serial number to use to install new operating system. Order the recovery disc or flash drive from the manufacturer this will install a new OS and put the system back to original and with all the correct drivers and a legal operating system using the original Windows key code which will be on the bottom of the lap top or net book..