Steam update stuck at 99%

I am having some trouble launching Steam. My PC was out of my home country for almost a year while I was changing jobs.

I am starting up a PC after almost a year. The PC remained in Spain, while I was changing jobs. I finally have it. :-)

I got a technician to verify that all parts are working properly.

I got all excited and started Steam to get this screen.

Steam 99% error

Since then each time I start Steam, same progress. It never goes beyond the 99% screen. My HDD are not grinding etc. I have enough RAM about 8 GB.

Can someone experienced in this help?


The recommendations over at the Steam forums are to allow Steam to finish updating while running Windows in Safe Mode - presumably some background application (like a third party firewall or antivirus program) is preventing Steam from updating in these instances.

To restart your computer in Safe Mode with Networking support you can do the following;

  • Load up Steam, wait till it's stuck on 99%.
  • Press "Start" button, type "msconfig" into the search bar and press enter.
  • Under the "Boot" tab where the "Boot options" are, tick "Safe boot" then select "Network".
  • Restart your computer and allow it to load up in safe mode.
  • Everything will most likely look big and ugly.
  • Load up Steam, once it completes the update, log in.
  • Press "Start" button, type "msconfig" into the search bar and press enter.
  • Under the "Boot" tab where the "Boot options" are, un-tick "Safe boot".
  • Restart in to normal Windows.
  • Run Steam successfully.

As an alternative to running msconfig to force Safe Mode with Networking, it is possible to achieve the same effect by pressing F8 at the correct point during Windows startup (just before the Windows logo first appears, after the power on self test has completed).

This of course, might not be the only solution to the problem you're experiencing. One other suggestion for resolving this problem is that by closing Steam and then deleting the clientregistry.blob file from within your Steam installation folder, you can complete updating the Steam client successfully.

Finally one other solution that I haven't come across before is using a utility called TCPView to close the connection from Steam during the update process, after it has stalled. This is detailed here in this Steam forum post and involves using a free Microsoft Sysinternals application called TCPView. The details on how to achieve this are as follows;

  • Download the TCPViewer application from Microsoft MSDN
  • Extract and run the TCPView.exe application only
  • Open the Steam, when it hangs during updating, open the TCPView.exe and find steam.exe inside the TCPView.exe program
  • Right click Steam.exe inside the TCPView programme and click close connection.

It could also just be that in the year or so since you've last used Steam on this computer it needs to download a sizeable update, which could take some time. The Steam updater can leave itself in a position where it looks like it's doing nothing but may require just a little patience before it springs back into life.


Have you tried to uninstall it and then install the Steam client from scratch? You can save your downloaded games if you wish so to don't waste time downloading them again.


First make sure Windows is up to date. Start Windows Update and let it install all available updates. These might not only fix issues, but will also slow your system down while they're installed in background.

Once this is done start steam and just let it run. This might take quite a bit, which is annoying, but don't worry, it should continue (you should see disk activity during this). If you're unlucky, this might take several hours to complete, depending on the amount of games being installed.

Background: A while ago Steam changed their archive/index file format. Due to this game clients have to verify the integrity of all local files and they might have to redownload some data as well. Unfortunately it can happen that the main window of steam won't appear for a while, while it's busy/working in background. I've had similar issues about half year ago and it took me quite some time of waiting.

If this doesn't work, delete or rename the file ClientRegistry.blob in your Steam directory while the client is not running. This file will be recreated the next time you start Steam, but it might still show the behavior I've described above.