Thanks Glenn.

I need to see if "$bbhomeext" is part of the string in "$bbexternals" and skip the writevalue section if it does.

Code:
 

$bbhome=ReadValue("HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Components\16FD58773EE02F44F9082F014DAF6CC9", "6BB86DA5D449506409F1448FC6560289")
 If @error <> 0
       ? "Error Encountered: " + @serror
       MessageBox("Can't find Big Brother install path!", $bbhome, 16)
       Exit 0
 Else
       $bbexternals = ReadValue ("HKEY_LOCAL_MACHINE\SOFTWARE\Quest Software\BigBrother\bbnt\Externals","")
       If @error = 0
             $bbfolder=$bbhome + "ext"
             $bbhomeext=";" + $bbfolder + "\" + "compaqhw.exe /INT=300"
             $bbhomeext1=$bbfolder + "\" + "compaqhw.exe /INT=300"
             If Not Exist($bbfolder)
                   MD $bbfolder
             EndIf
             If $bbexternals
                   $bbexternals=$bbexternals + $bbhomeext
             Else
                   $bbexternals=$bbhomeext1
             EndIf
             $ = WriteValue ("HKEY_LOCAL_MACHINE\SOFTWARE\Quest Software\BigBrother\bbnt\Externals","",$bbexternals,"REG_SZ")


I know I'm missing "endifs", but this is just a snippet.
_________________________
I could have made a neat retort but didn't, for I was flurried and didn't think of it till I was downstairs.
-Mark Twain