Disk Write Error in Steam is thrown at you while you try to download or update the game in your library. If you are an unfortunate user of Steam that has encountered this error do not sweat, the error is usually tied to permission in windows or file corruption and not to hardware issues and can be easily resolved.
In this guide, we will go through solutions for this specific error and it is advisable to go through solutions as they are presented since they go from the easiest and most common issues.

Restart PC and Steam
The easiest and quickest way of resolving this issue is just a simple restart of the Steam client. Just completely quit Steam and they run it again, if this has not solved the issue try rebooting your PC. In most cases, this can solve the issue since this error is known to be introduced with some communication issues with OS (Windows)
Set Write permissions
Disk write permissions could also cause this error because if by any chance the Steam library folder has been set or changed to the read-only client would be unable to write anything in it. To easily solve this issue completely exit the Steam client and rerun it as administrator. Just right-click on it and select Run as Administrator. If this has solved your issue run Steam always as an administrator.
To run always as an administrator right click on the steam executable, go to properties, and inside properties go to the compatibility tab. In the compatibility tab check run as administrator and click on OK.
Clear download cache
If for any reason cache has become corrupted there is a big chance that this might be an issue why there is a disk drive error in Steam. To clear download, cache goes into your client, and on top drow down menu click on steam. Find and open settings and inside go to the downloads tab. Locate a clear download cache and immediately you will be prompted to restart Steam. After restart, you will be asked to login into steam and the issue with disk write should be gone.
Repair library folder
Library folder issues can also be the source of disk write annoyance so let's repair them. Click steam in the top left and go to the settings. Locate and click on Downloads and then go to Steam library folders. You will be here shown all disk drivers you are using for steam games and all of the games that are downloaded.
Select the game you are getting errors with and click on three dots on the far right. From the menu choose the repair folder option. Take note that the more games you have installed, the more time the repair process will need.
Change download server
Sometimes the issue is not at your end at all, servers can experience problems and outrages and this can directly reflect at your end with a disk write error. If any of the previous solutions have not resolved the issue this is the next logical step to try. If the server is facing issues then changing the download server will resolve the issue at your end.
Click on settings in the top drop-down menu and then click on the Steam library folder. Find the downloads page and then click on download region, Choose another server than one nearest to your location since that's what will Steam choose by default.


The true cause is that there is no working Border Gateway Protocol (BGP) routes into Facebook's sites. BGP is the standardized exterior gateway protocol used to exchange routing and reachability information between the internet top-level autonomous systems (AS). Most people, indeed most network administrators, never need to deal with BGP.
Cloudflare VP Dane Knecht was the first to report the underlying BGP problem. This meant, as Kevin Beaumont, former Microsoft's Head of Security Operations Centre, tweeted,
"By not having BGP announcements for your DNS name servers, DNS falls apart = nobody can find you on the internet. Same with WhatsApp btw. Facebook has basically de-platformed themselves from their own platform."
Many people are very annoyed by this and with the fact that they cannot use their social media platforms but it seems that Facebook employees are in even bigger annoyance as it was reported that Facebook employees can't enter their buildings because their "smart" badges and doors were also disabled by this network failure. If true, Facebook's people literally can't enter the building to fix things.
Reddit user u/ramenporn, who claimed to be a Facebook employee working on bringing the social network back from the dead, reported, before he deleted his account and his messages:
"DNS for FB services has been affected and this is likely a symptom of the actual issue, and that's that BGP peering with Facebook peering routers has gone down, very likely due to a configuration change that went into effect shortly before the outages happened (started roughly 1540 UTC). There are people now trying to gain access to the peering routers to implement fixes, but the people with physical access is separate from the people with knowledge of how to actually authenticate to the systems and people who know what to actually do, so there is now a logistical challenge with getting all that knowledge unified. Part of this is also due to lower staffing in data centers due to pandemic measures."
Ramenporn also stated that it wasn't an attack, but a mistaken configuration change made via a web interface.
Both BGP and DNS are down, the "connection to the outside world is down, remote access to those tools don't exist anymore, so the emergency procedure is to gain physical access to the peering routers and do all the configuration locally."
Technicians on site don't know how to do that and senior network administrators aren't on site.
It seems that it will all be down for a couple of more hours before the issue is resolved. 