|Then you'll need to perform a factory recovery if there is a recovery partition on the hard drive. To access the recovery program you have to press a specific key at the boot splash-screen. That specific key varies on different makes of laptops.|
Look at the bottom of the splash-screen & it should tell you there which key to press and hold. For example, "press F2 for recovery" or F2 = recovery" (the 'F2' is just an example, yours may be different).
If there is no such information their, then you probably do not have a recovery partition. You can try contacting the laptop manufacturer for a replacement recovery disc if they have one. Some manufacturer's support websites provide information on how to order one, it depends how good their support is.