Click on start and type msconfig in the search bar, msconfig should be at the top of the list click on it or just press enter msconfig will open. On the general tab make sure normal start is ticked, click on apply and then OK restart the computer.
If you still have problems it could be something preventing the computer from starting correctly, this could be anything from corrupt files to the hard drive failing.
Try start/all programs/accessories right click on command prompt and select run as administrator type sfc /scannow (note the space between sfc and the /)this will check for system errors.
If you read the instructions that came with the laptop
Also try checking the drive for bad sectors, right click on drive/properties/tools/check now and select scan for and attempt recovery of bad sectors this will check the hard drive on next boot and can take a while. (note: Unlikely but if this shows too many errors you may need a new hard drive)
If you read the instructions that came with the laptop it will give you instructions on what the F key functions will do on boot up and how to restore the computer to factory default.
If F8 is the key to repair your computer make sure you save all your documents to an external drive and use this to rectify the problem if the above does not work.