The following code is what we use to achieve this:

*************************************************************************************
*$METHOD$ spIsProcessRunning()
*
*$PURPOSE$
* Searches through the task list and sees if the passed process is
* currently executing on the local machine.
*$PURPOSE$
*************************************************************************************
FUNCTION spIsProcessRunning
LPARAMETERS vcProcessName, rcErrors

#DEFINE PROCESS_QUERY_INFORMATION 0x400
#DEFINE PROCESS_VM_READ 0x10
#DEFINE PROCESS_ALL_ACCESS 0x1f0fff
#DEFINE PROCESS_MASK BITOR(PROCESS_QUERY_INFORMATION,PROCESS_VM_READ)

declare integer GetLastError in win32api
declare integer EnumProcesses in psapi string@, integer, integer@
declare integer EnumProcessModules in psapi integer, string@, integer, integer@
declare integer GetModuleFileNameEx in psapi integer, integer, string@, integer
declare integer OpenProcess in kernel32 integer, integer, integer
declare integer CloseHandle in kernel32 integer
declare string GetCommandLine in kernel32 integer

LOCAL lcPIDArray, lcModArray, lnSize, lnNeeded, lcArrstr, lnMod, llProcess, ;
lnNeeded, lnCount, lnHProc, lnModLen, lnCount2, llReturn, lcModName

lcPIDArray = REPLICATE(CHR(0), 4096)
lnSize = 200
lnNeeded = 0
lnModLen = 0

IF EnumProcesses(@lcPIDarray, lnSize, @lnNeeded) <> 0
lcPIDarray = LEFT(lcPIDarray,lnNeeded)

FOR lnCount = 1 TO lnNeeded STEP 4
lnPID = spStr2Long(SUBSTR(lcPIDArray, lnCount, 4))

IF lnPID <> 0
lnHProc = OpenProcess(PROCESS_MASK, 0, lnPID)

IF lnHProc <> 0
lcModArray = REPLICATE(CHR(0),8192)

IF EnumProcessModules(lnHProc, @lcModArray, lnSize, @lnModLen) <> 0
llProcess = .F.

FOR lnCount2 = 1 to 1 step 4
lnMod = spStr2Long(SUBSTR(lcModArray,lnCount2, 4))

IF lnMod <> 0
lcModName = REPLICATE(CHR(0),128)
GetModuleFileNameEx(lnHProc, lnMod, @lcModName, 128)

IF !llprocess AND (lnCount2 = 1 AND !("VFP" $ UPPER(lcModName)))
llprocess = .T.
ENDIF

IF !llprocess
EXIT
ENDIF

IF UPPER(JUSTFNAME(LEFT(lcModName,AT(CHR(0),lcModName)-1))) == UPPER(vcProcessName)
llReturn = .t.
EXIT
ENDIF
ENDIF

NEXT

ENDIF

CloseHandle(lnHProc)
ENDIF
ENDIF

IF llReturn
*-- We have a match so don't bother going any further
EXIT
ENDIF
NEXT
ELSE
*-- We have an error
rcError = transform(GetLastError())
ENDIF

RETURN llReturn
ENDFUNC

FUNCTION spStr2Long
LPARAMETERS vcLongStr

LOCAL lnCount, lnReturn

lnReturn = 0

FOR lnCount = 0 TO 24 STEP 8
lnReturn = lnReturn + (ASC(vcLongStr) * (2^lnCount))
vcLongStr = RIGHT(vcLongStr, LEN(vcLongStr) - 1)
NEXT
RETURN lnReturn
ENDFUNC