There's no clean copy of that file in the system.
Download the attachment to replace the infected file (it's the same version SP3).
and extract it to C:\
Close any open browsers.
Disable anti virus and anti malware programs so they do not interfere with the running of ComboFix.
Open notepad and copy/paste the text in the codebox below into it:
Fcopy::
C:\ws2_32.dll | c:\windows\system32\ws2_32.dll
C:\ws2_32.dll | c:\windows\ServicePackFiles\i386\ws2_32.dll
Save this as CFScript.txt, in the same location as ComboFix.exe
Then drag the CFScript.txt into ComboFix.exe. This will start ComboFix again and replace the infected file.