* Referenced by a CALL at Addresses:
|:00440C73   , :00440C83   , :0046C395   , :0046C3A6   , :004A06FC   
|:004A070D   
|
:0044E457 55                      push ebp
:0044E458 89E5                    mov ebp, esp
:0044E45A 53                      push ebx
:0044E45B 81ECF8010000            sub esp, 000001F8
:0044E461 57                      push edi
:0044E462 B8CCCCCCCC              mov eax, CCCCCCCC
:0044E467 8D7C2404                lea edi, dword ptr [esp+04]
:0044E46B B97E000000              mov ecx, 0000007E
:0044E470 F3                      repz
:0044E471 AB                      stosd
:0044E472 5F                      pop edi
:0044E473 8D8508FEFFFF            lea eax, dword ptr [ebp+FFFFFE08]
:0044E479 50                      push eax
:0044E47A FF7508                  push [ebp+08]
:0044E47D 68A80A5500              push 00550AA8
:0044E482 E8D44AFEFF              call 00432F5B
:0044E487 83C40C                  add esp, 0000000C
:0044E48A 6A00                    push 00000000
:0044E48C 8B1D3441D108            mov ebx, dword ptr [08D14134]
:0044E492 8D1CDB                  lea ebx, dword ptr [ebx+8*ebx]
:0044E495 01DB                    add ebx, ebx
:0044E497 8B0CDDC4080201          mov ecx, dword ptr [8*ebx+010208C4]
:0044E49E E8E65FFBFF              call 00404489
:0044E4A3 8B0D3441D108            mov ecx, dword ptr [08D14134]
:0044E4A9 69C990000000            imul ecx, 00000090
:0044E4AF 81C1C0080201            add ecx, 010208C0
:0044E4B5 E8B4F8FBFF              call 0040DD6E
:0044E4BA 6A00                    push 00000000
:0044E4BC 8B1D3441D108            mov ebx, dword ptr [08D14134]
:0044E4C2 8D1CDB                  lea ebx, dword ptr [ebx+8*ebx]
:0044E4C5 01DB                    add ebx, ebx
:0044E4C7 8B0CDDC4080201          mov ecx, dword ptr [8*ebx+010208C4]
:0044E4CE E8B65FFBFF              call 00404489
:0044E4D3 6A08                    push 00000008
:0044E4D5 8D8508FEFFFF            lea eax, dword ptr [ebp+FFFFFE08]
:0044E4DB 50                      push eax
:0044E4DC 8B0D3441D108            mov ecx, dword ptr [08D14134]
:0044E4E2 69C990000000            imul ecx, 00000090
:0044E4E8 81C1C0080201            add ecx, 010208C0
:0044E4EE E88166FCFF              call 00414B74
:0044E4F3 6A04                    push 00000004
:0044E4F5 8B1D3441D108            mov ebx, dword ptr [08D14134]
:0044E4FB 8D1CDB                  lea ebx, dword ptr [ebx+8*ebx]
:0044E4FE 01DB                    add ebx, ebx
:0044E500 8B0CDDC4080201          mov ecx, dword ptr [8*ebx+010208C4]
:0044E507 E86661FBFF              call 00404672
:0044E50C 50                      push eax
:0044E50D E82E61FBFF              call 00404640
:0044E512 59                      pop ecx
:0044E513 59                      pop ecx
:0044E514 3C00                    cmp al, 00
:0044E516 7407                    je 0044E51F
:0044E518 B800000000              mov eax, 00000000
:0044E51D EB76                    jmp 0044E595

* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:0044E516(C)
|
:0044E51F 6A01                    push 00000001
:0044E521 8B1D3441D108            mov ebx, dword ptr [08D14134]
:0044E527 8D1CDB                  lea ebx, dword ptr [ebx+8*ebx]
:0044E52A 01DB                    add ebx, ebx
:0044E52C 8B0CDDC4080201          mov ecx, dword ptr [8*ebx+010208C4]
:0044E533 E83A61FBFF              call 00404672
:0044E538 50                      push eax
:0044E539 E80261FBFF              call 00404640
:0044E53E 59                      pop ecx
:0044E53F 59                      pop ecx
:0044E540 3C00                    cmp al, 00
:0044E542 7407                    je 0044E54B
:0044E544 B800000000              mov eax, 00000000
:0044E549 EB4A                    jmp 0044E595

* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:0044E542(C)
|
:0044E54B 6A02                    push 00000002
:0044E54D 8B1D3441D108            mov ebx, dword ptr [08D14134]
:0044E553 8D1CDB                  lea ebx, dword ptr [ebx+8*ebx]
:0044E556 01DB                    add ebx, ebx
:0044E558 8B0CDDC4080201          mov ecx, dword ptr [8*ebx+010208C4]
:0044E55F E80E61FBFF              call 00404672
:0044E564 50                      push eax
:0044E565 E8D660FBFF              call 00404640
:0044E56A 59                      pop ecx
:0044E56B 59                      pop ecx
:0044E56C 3C00                    cmp al, 00
:0044E56E 7407                    je 0044E577
:0044E570 B800000000              mov eax, 00000000
:0044E575 EB1E                    jmp 0044E595

* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:0044E56E(C)
|
:0044E577 8B0D3441D108            mov ecx, dword ptr [08D14134]
:0044E57D 69C990000000            imul ecx, 00000090
:0044E583 81C1C0080201            add ecx, 010208C0
:0044E589 E8E0F7FBFF              call 0040DD6E
:0044E58E B801000000              mov eax, 00000001
:0044E593 EB00                    jmp 0044E595

* Referenced by a (U)nconditional or (C)onditional Jump at Addresses:
|:0044E51D(U), :0044E549(U), :0044E575(U), :0044E593(U)
|
:0044E595 8D65FC                  lea esp, dword ptr [ebp-04]
:0044E598 5B                      pop ebx
:0044E599 5D                      pop ebp
:0044E59A C3                      ret

:0046C35A 6813756100              push 00617513

* Possible StringData Ref from Data Obj ->"No VERSION-6.0 CD found! X-Plane "
                                        ->"is operating in demo mode."
                                  |
:0046C35F 683D756100              push 0061753D
:0046C364 6A00                    push 00000000
:0046C366 E87ED7FCFF              call 00439AE9
:0046C36B 83C418                  add esp, 00000018
:0046C36E C705506C640001000000    mov dword ptr [00646C50], 00000001

* Referenced by a (U)nconditional or (C)onditional Jump at Addresses:
|:0046C326(C), :0046C339(C), :0046C342(C)
|
:0046C378 833D506C640000          cmp dword ptr [00646C50], 00000000
:0046C37F 0F849B000000            je 0046C420
:0046C385 BA00000000              mov edx, 00000000
:0046C38A 8915506C6400            mov dword ptr [00646C50], edx

* Possible StringData Ref from Data Obj ->"FIDELITY BUILD.txt"
                                  |
:0046C390 6879756100              push 00617579
:0046C395 E8BD20FEFF              call 0044E457
:0046C39A 59                      pop ecx
:0046C39B 898518FDFFFF            mov dword ptr [ebp+FFFFFD18], eax

* Possible StringData Ref from Data Obj ->"HOW TO INSTALL VERSION 6.txt"
                                  |
:0046C3A1 688C756100              push 0061758C
:0046C3A6 E8AC20FEFF              call 0044E457
:0046C3AB 59                      pop ecx
:0046C3AC 89851CFDFFFF            mov dword ptr [ebp+FFFFFD1C], eax
:0046C3B2 BA00000000              mov edx, 00000000
:0046C3B7 31C0                    xor eax, eax
:0046C3B9 83BD18FDFFFF00          cmp dword ptr [ebp+FFFFFD18], 00000000
:0046C3C0 7505                    jne 0046C3C7
:0046C3C2 B801000000              mov eax, 00000001

* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:0046C3C0(C)
|
:0046C3C7 83F800                  cmp eax, 00000000
:0046C3CA 741A                    je 0046C3E6
:0046C3CC 31C0                    xor eax, eax
:0046C3CE 83BD1CFDFFFF00          cmp dword ptr [ebp+FFFFFD1C], 00000000
:0046C3D5 7505                    jne 0046C3DC
:0046C3D7 B801000000              mov eax, 00000001

* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:0046C3D5(C)
|
:0046C3DC 83F800                  cmp eax, 00000000
:0046C3DF 7405                    je 0046C3E6
:0046C3E1 BA01000000              mov edx, 00000001

* Referenced by a (U)nconditional or (C)onditional Jump at Addresses:
|:0046C3CA(C), :0046C3DF(C)
|
:0046C3E6 89150851B208            mov dword ptr [08B25108], edx
:0046C3EC 8B8518FDFFFF            mov eax, dword ptr [ebp+FFFFFD18]
:0046C3F2 A3F86E3001              mov dword ptr [01306EF8], eax
:0046C3F7 833D0851B20800          cmp dword ptr [08B25108], 00000000
:0046C3FE 7520                    jne 0046C420
:0046C400 6A0F                    push 0000000F
:0046C402 68A9756100              push 006175A9

* Possible StringData Ref from Data Obj ->"Next time put the CD in before "
                                        ->"you start X-Plane to avoid this "
                                        ->"annoyance!"
                                  |
:0046C407 68AA756100              push 006175AA

* Possible StringData Ref from Data Obj ->"I am taking you out of demo mode "
                                        ->"now!"
                                  |
:0046C40C 68F4756100              push 006175F4

* Possible StringData Ref from Data Obj ->"OK I found the CD!"
                                  |
:0046C411 681A766100              push 0061761A
:0046C416 6A00                    push 00000000
:0046C418 E8CCD6FCFF              call 00439AE9
:0046C41D 83C418                  add esp, 00000018

* Referenced by a (U)nconditional or (C)onditional Jump at Addresses:
|:0046C37F(C), :0046C3FE(C)
|
:0046C420 833D0851B20800          cmp dword ptr [08B25108], 00000000
:0046C427 0F8498000000            je 0046C4C5
:0046C42D D905B450B208            fld dword ptr [08B250B4]
:0046C433 D81DD06E6100            fcomp dword ptr [00616ED0]
:0046C439 DFE0                    fstsw ax
:0046C43B F6C445                  test ah, 45
:0046C43E 0F8581000000            jne 0046C4C5
:0046C444 833D486C640000          cmp dword ptr [00646C48], 00000000
:0046C44B 7578                    jne 0046C4C5
:0046C44D C705486C640001000000    mov dword ptr [00646C48], 00000001
:0046C457 6828495500              push 00554928
:0046C45C 68A80A5500              push 00550AA8

* Possible StringData Ref from Data Obj ->"I do not detect an X-Plane 6.0 "
                                        ->"or later CD in the following drive: "
                                  |
:0046C461 682D766100              push 0061762D
:0046C466 E8F06AFCFF              call 00432F5B
:0046C46B 83C40C                  add esp, 0000000C
:0046C46E 6828495500              push 00554928

* Possible StringData Ref from Data Obj ->" so I shall now ignore your joystick "
                                        ->"input since you have not put the "
                                        ->"X-Plane 6.0 or later CD in that "
                                        ->"drive!"
                                  |
:0046C473 6871766100              push 00617671
:0046C478 6828495500              push 00554928
:0046C47D E8D96AFCFF              call 00432F5B
:0046C482 83C40C                  add esp, 0000000C
:0046C485 6A0F                    push 0000000F
:0046C487 68A9756100              push 006175A9

* Possible StringData Ref from Data Obj ->"(If you already have an X-Plane "
                                        ->"6.0 or later CD, be sure to put "
                                        ->"it in the drive before you start "
                                        ->"the sim to avoid this message!)"
                                  |
:0046C48C 68DE766100              push 006176DE

How-to crack X-Plane 6.51
Used disassembler W32Dasm version 8.9

1) disasemble X-Plane 651.exe
2) find string "I do not detect an X-Plane 6.0" - is in the location code.txt :0046C45C
3) function called from addres :0046C395 - call 0044E457 is function, that returns in register EAX "00000000", if not in the CD-ROM original CD and "00000001", if found in CD-ROM original CD.
4) is demand ensure, that the function "function.txt" always returns in register EAX "00000001".
5) return from this function is possible from this addreses :0044E51D(U), :0044E549(U), :0044E575(U), :0044E593(U) In 3 first addreses is (one instruction back) mov eax,00000000 and in the last is 00000001.
6) in this 3 locations :0044E518, :0044E544, :0044E570 is demand this code: "B800000000 -- mov eax, 00000000" replace this new code: "B801000000 -- mov eax, 00000001"
7) In hexaeditor are this codes at there positions 4D918, 4D944, 4D970  replace this "b8 00 00 00 00" herewith : "b8 01 00 00 00".

thats all; 

Copy "X-Plane 651 crack.exe" to your directory contains file "X-Plane 651.exe".
Run "X-Plane 651 crack.exe".
Use button "Patch".

thats all;