$ProgramArray=GetUninstallInfo()

For Each $Program In $ProgramArray
	If $Program="your program"
		? "found it!"
	EndIf
Next 

Sleep 4 

Function GetUninstallInfo()
	Dim $Index, $Key, $RC, $Value, $RootKey
	Dim $progs[0]
	$Index = 0

	$RootKey = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\"

	$Key = EnumKey($RootKey, $Index)
	While @Error = 0
		ReDim PRESERVE $progs[$Index]
		$RC = EnumValue($RootKey + $Key, 1)
		If @Error = 0
			$Value = ReadValue($RootKey + $Key, "DisplayName")
			If $Value = ""
				$Value = ReadValue($RootKey + $Key, "QuietDisplayName")
				If $Value = ""
					$Value = $Key
				EndIf
			EndIf
		Else
			$Value = $Key
		EndIf
		;? $Value
		$progs[$Index] = $Value
		$Index = $Index + 1
		$Key = EnumKey($RootKey, $Index)
	Loop
	$GetUninstallInfo = $progs
EndFunction

Quote:

---

checks to see if a program is installed or not

---