网上也有相关解决办法，不过不怎么样，要么不详细，要么就是复制粘贴。不多说看图片：

第一：先安装C51(必须先安装C51，不能先安装ARM，否则会失败。)

第二：安装keil ARM(不能安装在同一个文件夹下)

我当前安装的是mdk arm4.53

第三：打开keil c51和keil arm 两个文件夹，分别找到tools.ini

分别打开两个“tools.ini”,将keil C51文件夹下的tools.ini文件中[C51]段复制到keil ARM中tools.ini文件的最后；将keil ARM文件夹下的tools.ini文件中[ARM]段复制到keil C51中tools.ini文件的最后：

tools.ini  -->keil ARM

[UV2]
ORGANIZATION="小川电子工作室"
NAME="小川电子工作室", "小川电子工作室"
EMAIL="paulhyde@126.com"
ARMSEL=1
BOOK0=UV4\RELEASE_NOTES.HTM("uVision Release Notes",GEN)
[ARM]
PATH="D:\Keil ARM\ARM\"
VERSION=4.50
PATH1="C:\Program Files\arm-none-eabi-gcc-4_6\"
TOOLPREFIX=arm-none-eabi-
CPUDLL0=SARM.DLL(TDRV0,TDRV5,TDRV6,TDRV10)    # Drivers for ARM7/9 devices
CPUDLL1=SARMCM3.DLL(TDRV1,TDRV2,TDRV3,TDRV4,TDRV5,TDRV7,TDRV8,TDRV9,TDRV11,TDRV12,TDRV13)    # Drivers for Cortex-M devices
CPUDLL2=SARMCR4.DLL(TDRV7)    # Drivers for Cortex-R4 devices
BOOK0=HLP\RELEASE_NOTES.HTM("Release Notes",GEN)
BOOK1=HLP\ARMTOOLS.chm("Complete User's Guide Selection",C)
BOOK2=HLP\RL_RELEASE_NOTES.HTM("RL-ARM Release Notes",GEN)
BOOK3=CMSIS\index.html("CMSIS Documentation",GEN)
TDRV0=BIN\UL2ARM.DLL("ULINK2/ME ARM Debugger")
TDRV1=BIN\UL2CM3.DLL("ULINK2/ME Cortex Debugger")
TDRV2=BIN\AGDIRDI.DLL("RDI Interface Driver")
TDRV3=BIN\ABLSTCM.dll("Altera Blaster Cortex Debugger")
TDRV4=BIN\lmidk-agdi.dll("Stellaris ICDI")
TDRV5=Signum\SigUV3Arm.dll("Signum Systems JTAGjet")
TDRV6=Segger\JLTAgdi.dll("J-LINK / J-TRACE")
TDRV7=Segger\JL2CM3.dll("Cortex-M/R J-LINK/J-Trace")
TDRV8=STLink\ST-LINKIII-KEIL.dll ("ST-Link (Deprecated Version)")
TDRV9=BIN\ULP2CM3.DLL("ULINK Pro Cortex Debugger")
TDRV10=BIN\ULP2ARM.DLL("ULINK Pro ARM Debugger")
TDRV11=NULink\Nu_Link.dll("NULink Debugger")
TDRV12=SiLabs\SLAB_CM_Keil.dll("SiLabs UDA Debugger")
TDRV13=STLink\ST-LINKIII-KEIL_SWO.dll ("ST-Link Debugger")
DELDRVPKG0=ULINK\UninstallULINK.exe("ULINK Pro Driver V1.0")
LIC0=ZB48T-RRRXD-GJE6P-M4J11-65JI1-GHTPN
BOOK4=Signum\Docs\SigUV3Arm.htm("Signum Systems JTAGjet Driver Documentation",GEN)
[ARMADS]
PATH="D:\Keil ARM\ARM\"
PATH1="BIN40\"
CPUDLL0=SARM.DLL(TDRV0,TDRV5,TDRV6,TDRV10)    # Drivers for ARM7/9 devices
CPUDLL1=SARMCM3.DLL(TDRV1,TDRV2,TDRV3,TDRV4,TDRV5,TDRV7,TDRV8,TDRV9,TDRV11,TDRV12,TDRV13)    # Drivers for Cortex-M devices
CPUDLL2=SARMCR4.DLL(TDRV7)    # Drivers for Cortex-R4 devices
BOOK0=HLP\RELEASE_NOTES.HTM("Release Notes",GEN)
BOOK1=HLP\ARMTOOLS.chm("Complete User's Guide Selection",C)
BOOK2=HLP\RL_RELEASE_NOTES.HTM("RL-ARM Release Notes",GEN)
BOOK3=CMSIS\index.html("CMSIS Documentation",GEN)
BOOK4=Signum\Docs\SigUV3Arm.htm("Signum Systems JTAGjet Driver Documentation",GEN)
TDRV0=BIN\UL2ARM.DLL("ULINK2/ME ARM Debugger")
TDRV1=BIN\UL2CM3.DLL("ULINK2/ME Cortex Debugger")
TDRV2=BIN\AGDIRDI.DLL("RDI Interface Driver")
TDRV3=BIN\ABLSTCM.dll("Altera Blaster Cortex Debugger")
TDRV4=BIN\lmidk-agdi.dll("Stellaris ICDI")
TDRV5=Signum\SigUV3Arm.dll("Signum Systems JTAGjet")
TDRV6=Segger\JLTAgdi.dll("J-LINK / J-TRACE")
TDRV7=Segger\JL2CM3.dll("Cortex-M/R J-LINK/J-Trace")
TDRV8=STLink\ST-LINKIII-KEIL.dll ("ST-Link (Deprecated Version)")
TDRV9=BIN\ULP2CM3.DLL("ULINK Pro Cortex Debugger")
TDRV10=BIN\ULP2ARM.DLL("ULINK Pro ARM Debugger")
TDRV11=NULink\Nu_Link.dll("NULink Debugger")
TDRV12=SiLabs\SLAB_CM_Keil.dll("SiLabs UDA Debugger")
TDRV13=STLink\ST-LINKIII-KEIL_SWO.dll ("ST-Link Debugger")
RTOS0=Dummy.DLL("Dummy")
RTOS1=VARTXARM.DLL ("RTX Kernel")
DELDRVPKG0=ULINK\UninstallULINK.exe("ULINK Pro Driver V1.0")
[C51]
PATH="D:\Keil C51\C51\"
VERSION=V9.06
BOOK0=HLP\Release_Notes.htm("Release Notes",GEN)
BOOK1=HLP\C51TOOLS.chm("Complete User's Guide Selection",C)
TDRV0=BIN\MON51.DLL ("Keil Monitor-51 Driver")
TDRV1=BIN\ISD51.DLL ("Keil ISD51 In-System Debugger")
TDRV2=BIN\MON390.DLL ("MON390: Dallas Contiguous Mode")
TDRV3=BIN\LPC2EMP.DLL ("LPC900 EPM Emulator/Programmer")
TDRV4=BIN\UL2UPSD.DLL ("ST-uPSD ULINK Driver")
TDRV5=BIN\UL2XC800.DLL ("Infineon XC800 ULINK Driver")
TDRV6=BIN\MONADI.DLL ("ADI Monitor Driver")
TDRV7=BIN\DAS2XC800.DLL ("Infineon DAS Client for XC800")
TDRV8=BIN\UL2LPC9.DLL ("NXP LPC95x ULINK Driver")
RTOS0=Dummy.DLL("Dummy")
RTOS1=RTXTINY.DLL ("RTX-51 Tiny")
RTOS2=RTX51.DLL ("RTX-51 Full")
LIC0=EXTEV-PIY1M-WN1AF-6K3HK-DRA7Y-FBXVW

keil-->c51

[UV2]
ORGANIZATION="小川工作室"
NAME="王川北", "111"
EMAIL="111"
BOOK0=UV4\RELEASE_NOTES.HTM("uVision Release Notes",GEN)
[C51]
PATH="D:\Keil C51\C51\"
VERSION=V9.06
BOOK0=HLP\Release_Notes.htm("Release Notes",GEN)
BOOK1=HLP\C51TOOLS.chm("Complete User's Guide Selection",C)
TDRV0=BIN\MON51.DLL ("Keil Monitor-51 Driver")
TDRV1=BIN\ISD51.DLL ("Keil ISD51 In-System Debugger")
TDRV2=BIN\MON390.DLL ("MON390: Dallas Contiguous Mode")
TDRV3=BIN\LPC2EMP.DLL ("LPC900 EPM Emulator/Programmer")
TDRV4=BIN\UL2UPSD.DLL ("ST-uPSD ULINK Driver")
TDRV5=BIN\UL2XC800.DLL ("Infineon XC800 ULINK Driver")
TDRV6=BIN\MONADI.DLL ("ADI Monitor Driver")
TDRV7=BIN\DAS2XC800.DLL ("Infineon DAS Client for XC800")
TDRV8=BIN\UL2LPC9.DLL ("NXP LPC95x ULINK Driver")
RTOS0=Dummy.DLL("Dummy")
RTOS1=RTXTINY.DLL ("RTX-51 Tiny")
RTOS2=RTX51.DLL ("RTX-51 Full")
LIC0=8V02Z-JIX83-09VG9-4M1JI-YKSD6-5KBQ3
[ARM]
PATH="D:\Keil ARM\ARM\"
VERSION=4.50
PATH1="C:\Program Files\arm-none-eabi-gcc-4_6\"
TOOLPREFIX=arm-none-eabi-
CPUDLL0=SARM.DLL(TDRV0,TDRV5,TDRV6,TDRV10)    # Drivers for ARM7/9 devices
CPUDLL1=SARMCM3.DLL(TDRV1,TDRV2,TDRV3,TDRV4,TDRV5,TDRV7,TDRV8,TDRV9,TDRV11,TDRV12,TDRV13)    # Drivers for Cortex-M devices
CPUDLL2=SARMCR4.DLL(TDRV7)    # Drivers for Cortex-R4 devices
BOOK0=HLP\RELEASE_NOTES.HTM("Release Notes",GEN)
BOOK1=HLP\ARMTOOLS.chm("Complete User's Guide Selection",C)
BOOK2=HLP\RL_RELEASE_NOTES.HTM("RL-ARM Release Notes",GEN)
BOOK3=CMSIS\index.html("CMSIS Documentation",GEN)
BOOK4=Signum\Docs\SigUV3Arm.htm("Signum Systems JTAGjet Driver Documentation",GEN)
TDRV0=BIN\UL2ARM.DLL("ULINK2/ME ARM Debugger")
TDRV1=BIN\UL2CM3.DLL("ULINK2/ME Cortex Debugger")
TDRV2=BIN\AGDIRDI.DLL("RDI Interface Driver")
TDRV3=BIN\ABLSTCM.dll("Altera Blaster Cortex Debugger")
TDRV4=BIN\lmidk-agdi.dll("Stellaris ICDI")
TDRV5=Signum\SigUV3Arm.dll("Signum Systems JTAGjet")
TDRV6=Segger\JLTAgdi.dll("J-LINK / J-TRACE")
TDRV7=Segger\JL2CM3.dll("Cortex-M/R J-LINK/J-Trace")
TDRV8=STLink\ST-LINKIII-KEIL.dll ("ST-Link (Deprecated Version)")
TDRV9=BIN\ULP2CM3.DLL("ULINK Pro Cortex Debugger")
TDRV10=BIN\ULP2ARM.DLL("ULINK Pro ARM Debugger")
TDRV11=NULink\Nu_Link.dll("NULink Debugger")
TDRV12=SiLabs\SLAB_CM_Keil.dll("SiLabs UDA Debugger")
TDRV13=STLink\ST-LINKIII-KEIL_SWO.dll ("ST-Link Debugger")
DELDRVPKG0=ULINK\UninstallULINK.exe("ULINK Pro Driver V1.0")
LIC0=UJWBS-LNGB0-8FWIE-5N2GJ-UKXD9-NTBGM
[ARMADS]
PATH="D:\Keil ARM\ARM\"
PATH1="BIN40\"
CPUDLL0=SARM.DLL(TDRV0,TDRV5,TDRV6,TDRV10)    # Drivers for ARM7/9 devices
CPUDLL1=SARMCM3.DLL(TDRV1,TDRV2,TDRV3,TDRV4,TDRV5,TDRV7,TDRV8,TDRV9,TDRV11,TDRV12,TDRV13)    # Drivers for Cortex-M devices
CPUDLL2=SARMCR4.DLL(TDRV7)    # Drivers for Cortex-R4 devices
BOOK0=HLP\RELEASE_NOTES.HTM("Release Notes",GEN)
BOOK1=HLP\ARMTOOLS.chm("Complete User's Guide Selection",C)
BOOK2=HLP\RL_RELEASE_NOTES.HTM("RL-ARM Release Notes",GEN)
BOOK3=CMSIS\index.html("CMSIS Documentation",GEN)
BOOK4=Signum\Docs\SigUV3Arm.htm("Signum Systems JTAGjet Driver Documentation",GEN)
TDRV0=BIN\UL2ARM.DLL("ULINK2/ME ARM Debugger")
TDRV1=BIN\UL2CM3.DLL("ULINK2/ME Cortex Debugger")
TDRV2=BIN\AGDIRDI.DLL("RDI Interface Driver")
TDRV3=BIN\ABLSTCM.dll("Altera Blaster Cortex Debugger")
TDRV4=BIN\lmidk-agdi.dll("Stellaris ICDI")
TDRV5=Signum\SigUV3Arm.dll("Signum Systems JTAGjet")
TDRV6=Segger\JLTAgdi.dll("J-LINK / J-TRACE")
TDRV7=Segger\JL2CM3.dll("Cortex-M/R J-LINK/J-Trace")
TDRV8=STLink\ST-LINKIII-KEIL.dll ("ST-Link (Deprecated Version)")
TDRV9=BIN\ULP2CM3.DLL("ULINK Pro Cortex Debugger")
TDRV10=BIN\ULP2ARM.DLL("ULINK Pro ARM Debugger")
TDRV11=NULink\Nu_Link.dll("NULink Debugger")
TDRV12=SiLabs\SLAB_CM_Keil.dll("SiLabs UDA Debugger")
TDRV13=STLink\ST-LINKIII-KEIL_SWO.dll ("ST-Link Debugger")
RTOS0=Dummy.DLL("Dummy")
RTOS1=VARTXARM.DLL ("RTX Kernel")
DELDRVPKG0=ULINK\UninstallULINK.exe("ULINK Pro Driver V1.0")

打开keil进行破解，此处不说明破解过程，请支持正版噢！