Unfortunate Dell doesn't list any windows 10 drivers for your computer - see link below): Support for Latitude E5520 | Drivers & Downloads | Dell US However, you could still upgrade to windows 10 and let windows updates install the necessary drivers for the computer. If needed, install older Windows 8 or earlier drivers in compatibility mode as ejn63 suggested. If you decide to upgrade to windows 10, I strongly suggest backing up all your photos, data and any important stuff to an external drive, cloud or backup software before upgrading to windows 10. Macrium Software | Reflect Free Edition Lastly,  If you aren't comfortable installing windows 10 onto the computer, I suggest considering installing Linux. 
I have a dell latitude E 5520 laptop so should I upgrade it to windows 10. and if yes then can you provide links to driver download for windows 10>.
Should I upgrade my Latitude E5520 to windows 10?