Цитата dmytriy_hryhorchuk@vk:
Из папки "User Data" удалите всё, кроме папок "Default", "Profile 1", "Profile 2" и подобные им.
Также сравните ассоциацию:
Код:

Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Classes\steam]
@="URL:steam protocol"
"URL Protocol"=""
[HKEY_CURRENT_USER\Software\Classes\steam\DefaultIcon]
@="steam.exe"
[HKEY_CURRENT_USER\Software\Classes\steam\Shell\Open\Command]
@="\"C:\\Program Files\\Steam\\steam.exe\" \"%1\""
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\steam]
@="URL:steam protocol"
"URL Protocol"=""
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\steam\DefaultIcon]
@="steam.exe"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\steam\Shell\Open\Command]
@="\"C:\\Program Files\\Steam\\steam.exe\" \"%1\""