Data recovery software is one option. The link MysteriousGX provided is a good start, tho you can always try looking for something yourself. There is free data recovery software out there, but most of it is limited in some way like only able to recover so many Mb/Gbs. This is all assuming the drive space where your files were hasn't been overwritten yet, hence MysteriousGX recommendation to download it on a different computer.
You can also try using the Command Prompt to recover files using the
chkdsk command. It's success rate isn't great, and it's not the most user-friendly method, but it doesn't require buying/installing any software. There's a rundown of it here:
How to recover files using CMD? This post gives you detailed steps for data recovery in different situations.
www.minitool.com
If that doesn't work, the final option is taking it to a
data recovery center, as per Gordon_4's advice. Keep in mind tho that their services can potentially cost you several hundred dollars, and there is still no guarantee they'll be able to recover all your data, and whatever is recovered may end up corrupted.
And lastly, a lot will depend on what kind of drive your files were on. If it is a mechanical HDD, then all of the above can work.
if you're on an SSD tho, then things can get dicier, because a lot of SSD's are subject to TRIM, and while that does help the speed and longevity of your drive, it often also means any file deleted from it is gone forever immediately, even if it wasn't overwritten, possibly beyond even the means of a data recovery center to fix.