Here's what it says in AppCrashView:

Version=1
EventType=CLR20r3
EventTime=129979469384836025
ReportType=2
Consent=1
UploadTime=129979469387577038
ReportIdentifier=c270e61b-3396-11e2-be76-001e68cde298
WOW64=1
Response.BucketId=023d0eb72539f71500652b1706925089
Response.BucketTable=5
Response.LegacyBucketId=-919724383
Response.type=4
Sig[0].Name=Problem Signature 01
Sig[0].Value=launchiw5m.exe
Sig[1].Name=Problem Signature 02
Sig[1].Value=1.0.0.0
Sig[2].Name=Problem Signature 03
Sig[2].Value=50242e08
Sig[3].Name=Problem Signature 04
Sig[3].Value=mscorlib
Sig[4].Name=Problem Signature 05
Sig[4].Value=2.0.0.0
Sig[5].Name=Problem Signature 06
Sig[5].Value=504a83a2
Sig[6].Name=Problem Signature 07
Sig[6].Value=3454
Sig[7].Name=Problem Signature 08
Sig[7].Value=d8
Sig[8].Name=Problem Signature 09
Sig[8].Value=System.IO.FileNotFoundException
DynamicSig[1].Name=OS Version
DynamicSig[1].Value=6.2.9200.2.0.0.256.48
DynamicSig[2].Name=Locale ID
DynamicSig[2].Value=1033
UI[2]=C:\Users\Nick\Downloads\Call of Duty Modern Warfare 3\FILES\LaunchIW5M.exe
UI[3]=LaunchIW5M has stopped working
UI[4]=Windows can check online for a solution to the problem.
UI[5]=Check online for a solution and close the program
UI[6]=Check online for a solution later and close the program
UI[7]=Close the program
LoadedModule[0]=C:\Users\Nick\Downloads\Call of Duty Modern Warfare 3\FILES\LaunchIW5M.exe
LoadedModule[1]=C:\WINDOWS\SYSTEM32\ntdll.dll
LoadedModule[2]=C:\WINDOWS\SYSTEM32\MSCOREE.DLL
LoadedModule[3]=C:\WINDOWS\SYSTEM32\KERNEL32.dll
LoadedModule[4]=C:\WINDOWS\SYSTEM32\KERNELBASE.dll
LoadedModule[5]=C:\WINDOWS\system32\apphelp.dll
LoadedModule[6]=C:\WINDOWS\AppPatch\AcLayers.DLL
LoadedModule[7]=C:\WINDOWS\SYSTEM32\msvcrt.dll
LoadedModule[8]=C:\WINDOWS\SYSTEM32\USER32.dll
LoadedModule[9]=C:\WINDOWS\SYSTEM32\GDI32.dll
LoadedModule[10]=C:\WINDOWS\SYSTEM32\SHELL32.dll
LoadedModule[11]=C:\WINDOWS\SYSTEM32\SHLWAPI.dll
LoadedModule[12]=C:\WINDOWS\SYSTEM32\OLEAUT32.dll
LoadedModule[13]=C:\WINDOWS\SYSTEM32\MPR.dll
LoadedModule[14]=C:\WINDOWS\SYSTEM32\SETUPAPI.dll
LoadedModule[15]=C:\WINDOWS\SYSTEM32\sfc.dll
LoadedModule[16]=C:\WINDOWS\SYSTEM32\WINSPOOL.DRV
LoadedModule[17]=C:\WINDOWS\SYSTEM32\RPCRT4.dll
LoadedModule[18]=C:\WINDOWS\SYSTEM32\combase.dll
LoadedModule[19]=C:\WINDOWS\SYSTEM32\CFGMGR32.dll
LoadedModule[20]=C:\WINDOWS\SYSTEM32\DEVOBJ.dll
LoadedModule[21]=C:\WINDOWS\SYSTEM32\SspiCli.dll
LoadedModule[22]=C:\WINDOWS\SYSTEM32\sfc_os.DLL
LoadedModule[23]=C:\WINDOWS\SYSTEM32\CRYPTBASE.dll
LoadedModule[24]=C:\WINDOWS\SYSTEM32\sechost.dll
LoadedModule[25]=C:\WINDOWS\SYSTEM32\bcryptPrimitives.dll
LoadedModule[26]=C:\WINDOWS\SYSTEM32\SortWindows61.dll
LoadedModule[27]=C:\WINDOWS\system32\IMM32.DLL
LoadedModule[28]=C:\WINDOWS\SYSTEM32\MSCTF.dll
LoadedModule[29]=C:\PROGRA~2\SEARCH~1\Datamngr\datamngr.dll
LoadedModule[30]=C:\WINDOWS\SYSTEM32\VERSION.dll
LoadedModule[31]=C:\WINDOWS\SYSTEM32\WTSAPI32.dll
LoadedModule[32]=C:\WINDOWS\SYSTEM32\ADVAPI32.dll
LoadedModule[33]=C:\WINDOWS\SYSTEM32\dbghelp.dll
LoadedModule[34]=C:\PROGRA~2\SEARCH~1\Datamngr\IEBHO.dll
LoadedModule[35]=C:\Windows\Microsoft.NET\Framework\v4.0.30319\mscoreei.dll
LoadedModule[36]=C:\Windows\Microsoft.NET\Framework\v2.0.50727\mscorwks.dll
LoadedModule[37]=C:\WINDOWS\WinSxS\x86_microsoft.vc80.crt_1fc8b3b9a1e18e3b_8.0.50727.6910_none_d089c358442de345\MSVCR80.dll
LoadedModule[38]=C:\WINDOWS\SYSTEM32\SHCORE.dll
LoadedModule[39]=C:\WINDOWS\SYSTEM32\profapi.dll
LoadedModule[40]=C:\WINDOWS\assembly\NativeImages_v2.0.50727_32\mscorlib\0d4a97f42b4d71125220c04a3a2fee75\mscorlib.ni.dll
LoadedModule[41]=C:\WINDOWS\SYSTEM32\ole32.dll
LoadedModule[42]=C:\WINDOWS\system32\uxtheme.dll
LoadedModule[43]=C:\Windows\Microsoft.NET\Framework\v2.0.50727\mscorjit.dll
LoadedModule[44]=C:\WINDOWS\SYSTEM32\CRYPTSP.dll
LoadedModule[45]=C:\WINDOWS\system32\rsaenh.dll
LoadedModule[46]=C:\Users\Nick\Downloads\Call of Duty Modern Warfare 3\FILES\DBNetwork.Indigo.dll
LoadedModule[47]=C:\WINDOWS\assembly\NativeImages_v2.0.50727_32\System\7a3f4b6e28bff7fc6e201f3444e38d06\System.ni.dll
LoadedModule[48]=C:\WINDOWS\assembly\NativeImages_v2.0.50727_32\System.Drawing\a2ce5fa5ddc467113d344183228ad23e\System.Drawing.ni.dll
LoadedModule[49]=C:\WINDOWS\assembly\NativeImages_v2.0.50727_32\System.Windows.Forms\b5fbb0525df9de99970c60a5891939eb\System.Windows.Forms.ni.dll
State[0].Key=Transport.DoneStage1
State[0].Value=1
FriendlyEventName=Stopped working
ConsentKey=CLR20r3
AppName=LaunchIW5M
AppPath=C:\Users\Nick\Downloads\Call of Duty Modern Warfare 3\FILES\LaunchIW5M.exe
ReportDescription=Stopped working

Also i already ran in admin mode, still doesn't work, turned off firewall, no diff., added to firewall list, still didn't work. By the by, i'm running windows 8 and ran it in Windows 7 compatibility mode, still didn't work. Please help me out here

EventType=CLR20r3

DynamicSig[1].Name=OS Version

DynamicSig[1].Value=6.2.9200.2.0.0.256.48

You have to enable .net Framework 3.5 on windows features, on windows 8. It should have popup to install .net Framework 3.5 when you first started LaunchIW5M.exe