Why MT4 could not run in windows 98 after installment ?

 
Why MT4 could not run in windows 98 (1st ed) after installment ? Have test many times without result, the mt4 can not be run after mt4 icon has been clicked. I notice the last version beta of mt4 that can run on windows 98 is version 146, after that all version of mt4 could not run. MT3 always can run even with the new version of 3.86. MT 4 can run on winxp but fail on win 98. This problem almost the same with icts-fx software which only could run on winxp, is mt4 specifically for win xp ?