How can I repair my website project after reinstalling Windows?

Before reinstalling Windows 10 on my computer, I have backed up the Website's folder that was inside Wamp/www/ . After I've reinstalled Windows 10 and WAMP, I've copy/pasted the folder back to it's original location (the path remained the same). I've started WAMP with no issues, but when I've opened the index page and the other pages (PHP and HTML) all the CSS, JavaScript, PHP and images/videos resources were completely lost, only the HTML structure was displayed.

I've compared the latest backup with an older backup that I've found and I've noticed two things:

1) The resources and CSS files from inside the latest backup have been corrupted somehow, images/videos can't even be opened and all the CSS files, including bootstrap, are empty when opened. The file size appears unchanged though.

2) On the older version, everything is there as it should be, but the website only displays the image/video resources and not the CSS.

I've checked everything inside the HTML/PHP code and everything is where it was when it last worked. All paths remained the same, including the ones inside the "link rel=… "

PHP is installed and configured (I've tested it and it works). It's also the same version as before: 7.3.12 .

I have tried to manually recreate a page, but to no avail.

Is there a way to recover the integrity of the files of my website, or do I have to start over?