Try contacting Sony customer support; they may be able to send you disks for the cost of postage.
Alternatively you may have to use your model number to download and back up all the drivers for your computer; and then use a windows Operating system disk to reformat your PC using the serial number which is on a sticker usually located on the underside of your laptop.
(After reformatting then use the drivers you backed up to restore all the hardware's functions)