Simplify the following text for a Grade 9 native English-speaking person.
Original: To do so would require re-architecting a very significant amount of the Microsoft Windows 2000 Service Pack 4 operating system , ( ... ) there would be no assurance that applications designed to run on Microsoft Windows 2000 Service Pack 4 would continue to operate on the updated system . ''
Simplified: Microsoft has said that they will not release a Service Pack 5 , but instead , have offered an `` Update Rollup '' for Service Pack 4 . Microsoft stopped developing their Java Virtual Machine ( JVM ) for Windows 2000 in Service Pack 3 .