OK. I downloaded this version, install the patches and it was working fine. 3 days ago I installed the 17 and 18 patches, and today when I try to run CSS I get an error on my Windows 7 Ultimate "HL2.EXE HAS STOPPED WORKING"  and theese are the problem details:
"Problem signature:
  Problem Event Name:    APPCRASH
  Application Name:    hl2.exe
  Application Version:    0.0.0.0
  Application Timestamp:    4c354523
  Fault Module Name:    steamclient.dll
  Fault Module Version:    0.0.0.0
  Fault Module Timestamp:    4c8fdf20
  Exception Code:    c0000005
  Exception Offset:    0002e545
  OS Version:    6.1.7600.2.0.0.256.1
  Locale ID:    1071
  Additional Information 1:    0a9e
  Additional Information 2:    0a9e372d3b4ad19135b953a78882e789
  Additional Information 3:    0a9e
  Additional Information 4:    0a9e372d3b4ad19135b953a78882e789

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If the online privacy statement is not available, please read our privacy statement offline:
  C:\Windows\system32\en-US\erofflps.txt
"

Can anyone tell me whats going on, and how can I fix this??

Same thing happend to me. Whats da deal?? Can anyone answer? Does anyone has a solution??