Ever heard of the C:\Windows\CSC folder? Me neither, but I noticed recently that a scanning program I was running was stuck on this folder, sifting through thousands and thousands of files. The folder appeared to be otherwise empty and Windows wouldn’t let me open it to see what was in it. After a quick Internet search, I learned that CSC stood for Client Side Cache; it’s where Windows keeps copies of network files and folders so you can use them if the network goes down. This feature is enabled by default. Based on what I was seeing, I knew there were a lot of files being stored there, but I didn’t think it would end up being 75GB!
For me, it seemed like a total unnecessary waste of disk space and I looked for a way to turn the feature off. At a very minimum, I wanted to clear it out and start fresh. It probably had tons of ancient files still cached that I’d never need. Note that this is really only an issue if you connect your computer to a network; however, even if you don’t have a home network, perhaps it’s a laptop that has been used on a network, like at work.
Unfortunately, you can’t just delete the files within the CSC folder. There are couple things you need to do first and here are the steps. (Note that this is a semi-advanced tutorial so proceed at your own risk.):

That’s it. Hope this frees some space for you!
RAM Freed up too???
An unexpected benefit is that my RAM usage seems to have been reduced by about 10-15%. I’m hoping this is an unexpected side benefit and will monitor. I guess if you think about it, Windows would need a lot of memory to cache all of the network files in real-time. Anyways, fingers are crossed ;-)
I don’t know if this is increasing the overall “shittiness of the internet” but it helped solve my on little private “90G of conflicts shittiness” problem (when iMazing tried to backup my 128G phone into an offline path, which I thought wasn’t being synced but was). To restore to the previous level of nirvana, I re-initialized my Client Side Cache (CSC) files by following this guide: https://docs.microsoft.com/en-us/troubleshoot/windows-client/networking/re-initialize-offline-files-cache-database
ugh. people who don’t know what they’re doing giving shitty advice to others, increasing the overall shittiness of the internet. you DO NOT change permissions on the CSC folder. do it the right way, disable offline files and format the CSC cache.
thanks for this post. Freed up 90 GB!! I had no idea windows cached network files, but it was caching a bunch of stuff from my NAS.
Your welcome!