this copy is not genuine build 7601

i bought a used laptop with windows 7 installed now my laptop says windows 7 build 7601 this copy is not genuine. i downloaded MGADiag and ran it this is tDiagnostic Report (1.9.0027.0): ----------------------------------------- Windows Validation Data--> Validation Code: 50 Cached Online Validation Code: 0x0 Windows Product Key: *****-*****-TMVMJ-BBMRX-3MBMV Windows Product Key Hash:...