$objConn is being used as a paramater to function so it can not be declared.

Remove $objConn from your Global declares.

Code:
Break On
Call @ScriptDir+'\'+'info.udf'
 
Dim $SO
Global $StartTime
$SO=SetOption('Explicit','On')
$SO=SetOption('NoVarsInStrings','On')
$StartTime=@TICKS
 
Global $,$ADMIN,$ADSite,$AllDesktop,$AllStartMenu,$CPU,$CSD,$CommonAppData,$ConnDSN,$CurrentIP,
$CurrentOS,$DNSHostName,$Date,$Desktop,$Dimm,$DomainMemberOf,$Favorites,$FreeSpace,$FullName,
$HKCUSMWCV,$HKCUSMWNTCV,$HKLMSCCS,$HKLMSMWCV,$HKLMSMWCVAP,$HKLMSMWNTCV,$HomeDirectory,$HomeDrive,
$HostComment,$HostName,$IE,$InstallDate,$Item,$LogonServer,$Patch,$BU,$MAC,
$MaxPWAge,$McAfeeInfo,$Mhz,$NAVInfo,$NT2KXP,$NoNAVFound,$OfficeApps,$OpenFile,
$PWAge,$PassExpires,$ProdType,$Ram,$ST,$ScriptRunTime,$Server,$SoftWareLog,$StartMenu,$StopTime,
$SystemLog,$SystemUpTime,$Time,$UserComment,$UserID,$MyVideoInfo,$MyCDInfo,$MyBIOSInfo,$sSrvc,
$sTrgt,$ServiceName,$State,$StartMode,$SMSSite,$UserList,$LT,$MDAC,$NMPath,$NMApp,$VMWUser,
$VMWPath,$VMWVer,$VMWToolsVer,$CVMVer,$CVMMapper,$CVMMapperVer,$ATVPN,$SMSFound,$SAPVersion,
$HTMLLog,$ImageLocation,$MySoftware,$Explorer,$MyImage,$PList,$SList,$HDList,$SUList,$NetFrameVer
 
$ConnDSN = "DRIVER={MySQL ODBC 3.51 Driver};SERVER=localhost;DATABASE=test;USER=test;PASSWORD='';OPTION=3;"
$objConn = DBConnOpen($ConnDSN)
? "Error : " + @ERROR + " " + @SERROR
Sleep 2
$sql = "INSERT INTO computer(name) VALUES('testcomputer')"
DBExecuteSQL($objConn,$sql)
? "Error : " + @ERROR + " " + @SERROR
Sleep 2
DBConnClose($objConn)
? "Error : " + @ERROR + " " + @SERROR
Sleep 2