It looks like similar users share your frustration for this annoyingly horrible issue:
However, it seems there are several fixes for this that have worked for other users:
Rolo: for me, this problem was caused by a optional windows update, ralink wlan 802.11n usb wireless lan card. I fixed it by going to device manager, network adapters, driver, roll back drivers. hope this helps someone.
Solution B (similar to A, for Win7):
Seismoid: I had the same problem with my steam client ("Could not connect to
steam network", then after deleting everything but steam.exe and
/steamapps folder "steam client has to be online to update", then
after uninstalling steam and trying to reinstall it took ~20 tries
until it downloaded the 110mb without error, but still kept getting
errors that it could not connect to steam network). In my case I just
took a look at the windows update history (win7) and found out that
the wlan driver was updated on march 5th. So I rolled back that update
and everything worked again. You might want to give it a try if you
have similar issues with your steam client as those mentioned in this
(I use Windows 7) First you should check if there is an update of your
wireless driver in the update history.
- Go to Control Panel -> System and Security -> Windows Update
- On the left side click "View update history"
- Look for a line that says "Ralink - WLAN - ..." (in my case it was "Ralink - WLAN - D-Link DWA-140 RAngeBooster N USB Adapter", my wlan
stick); hint: you just have to check the last 2-3 weeks - or whenever
your steam client stopped working - so sort the updates by a click on
"Date Installed" at the top ;)
- If there was an update and you want to try to roll back:
- go to Control Panel -> System and Security -> System
- click on "Device Manager" on the left side
- expand the "Network adapters" node in the device tree
- right-click on your wireless adapter mentioned earlier (here it only says "D-Link DWA-140 ..." - no "Ralink - WLAN -" as prefix)
- choose "Properties" in the context menu
- go to the "Driver" tab and click "Roll Back Driver"
- wait until windows is done rolling back (you may need to restart; though I didn't have to)
- dont install those drivers again if steam client works now :) (might need to deactivate automatic windows updates)
It seems in most of the cases, Steam's problem stems from a bad Wi-fi or network driver. It also doesn't hurt to check your antivirus or any firewalls running. See if disabling all anti-virus software while running Steam should work. Some users have found that their AVs were in fact blocking Steam.