1. Use the Installation Disk/CD - (if you
Usually your computers comes with installation disk/CD/DVD, you may have more than one disk/CD/DVD. One of the disk contains drivers for your computers. What you need to do is insert the disk into CD/DVD-ROM and run the setup to install the drivers. You can identify the Drivers installation disk by looking at the cover written "drivers and utility" or similar.
2. Download from second device and transfer it to your computers.
If you have other device that do have internet connection, you can use it to download the drivers for your computers and transfer it via USB cable/ThumbDrive etc. Example, if you have an iPad, browse the internet and go the manufacture site and then search your model within the manufacture site. Download the drivers and transfer it to your computers.
3. Using Restore/Recovery CD.
Most notebooks manufacture provide recovery CD, insert your recovery CD and follow the on-screen instruction to complete the process.
4. Look for driver backup in your hard-disk (Sometimes Hidden)
This option available if you didn't wipe out your entire disk for windows installation. If you install windows Vista/7/8 over previous installation (install without formatting) or (upgrade), you will have a Windows.Old folder on your c drive. If you open that folder you will see your original files store in that folder. If you are using notebook there are a great chance that your drivers are in the folder. For example Hp product will have Swsetup folder in the windows.old drive, Dell will have dell folder, Toshiba will have "driver" folder, similarly with other laptop. Sometimes, you just did not notice the company already make drivers backup on your other partition (D/E).
5. Final Option - Cybercafe
This will cost you some dollars to go and download your drivers - store it in CD/external storage, but better than repair shop fee.
Make sure to backup your drivers on Mass storage Device (pendrive/card reader/external hard disk etc) or CD/DVD for future use and never trash any recover/drivers CD provided by the manufacture.
Make sure you have all the drivers needed before installing new Operating System and check whether your manufacture support the Operating System of your choice or not.