In addition to Sergeys answer:

You won't be able to release the instance of Excel from memory if you have ANY reference to it. Look at this example

loExcel=Createobject('excel.application') && lcExcel is one reference to Excel in memory
loWB=loExcel.Workbooks.Open(lcFile) && loWB is another reference
loSheet= loWB.Sheets(lnSheet) && loSheet is a third reference
* Typically you have even more references. Now to remove Excel from memory, you must try to remove each reference IN REVERSE ORDER
* This means that you can't release a variable as long as another variable depends on it, so to say
loSheet=.null.
release loSheet
loWB=.null.
release loWB
loExcel=.null.
release loExcel && Now Excel is released from memory since also loSheet and loWB are released.

>Dear,
>
>I need to close the excel file even if attempt below code but does not close the excel process
>
>loExcel.quit
>loExcel=null
>
>this is happened when when I try to open xlsx file thru office 2003 platform ,needless to say I hv done convertion tools from xlsx to xls file
>fyi, it is opening thru normal excel operation but failed in vfp automation error msg "The server threw an exception".