Whats this mean and how do i fix it?

[GBH]

Product
hl2.exe

Problem
Stopped working

Date
5/23/2007 1:21 PM

Status
Not Reported

Problem signature
Problem Event Name: APPCRASH
Application Name: hl2.exe
Application Version: 0.0.0.0
Application Timestamp: 4445c334
Fault Module Name: datacache.dll
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 44721f59
Exception Code: c0000005
Exception Offset: 0000b413
OS Version: 6.0.6000.2.0.0.768.2
Locale ID: 1033
Additional Information 1: d28a
Additional Information 2: f2787b5a2f6112cb0d76a59eb1997f73
Additional Information 3: 3e15
Additional Information 4: d2260461d50b25e0a56354875cffb5a2

[Vreki]

It means the Hl2.exe crashed because of an error in datacache.dll

Try doing a google search on datacache.dll and crash, it should bring up several suggestions.