Hello,
We apologize for the long delay.
To resolve issues with the Steam client, please try the following.
Please exit Steam and go to the folder called C:\Program Files\Steam\ (this is the default location for a Steam installation - if you set a different installation directory, you will need to browse to it).
Delete all of the files in this folder except:
The \Steamapps\ folder and Steam.exe (this file is listed as an application and features the black and white Steam logo)
Restart your computer.
Then, launch Steam.exe from within the Steam installation folder, and not from a pre-existing shortcut.
With Steam running, re-test the original issue.
Note: This process will not affect your currently installed games.
If the issue persists, make sure your network is optimized for Steam:
Title: Troubleshooting Network Connectivity
Link:
http://support.steampowered.com/kb_article.php?ref=1456-EUDN-2493