https://community.hpe.com/t5/disk-enclosures/rebuild-raid-5/m-p/2768615#M5534 No you do not. Please make sure that Dynamic Disks are enabled. Then you can expand your existing array. If it is not then you cannot do what you ask. I have attached a document which will show you what to expect. This is for NT but it is pretty much the same. Tue, 30 Jul 2002 23:00:00 GMT Mark Cloutier 2002-07-30T23:00:00Z https://community.hpe.com/t5/disk-enclosures/rebuild-raid-5/m-p/2768614#M5533 I have a Compaq ProLiant ML350RG2 with three 18.2GB pluggable Wide Ultra3 hard drives. RAID-5 is formed among three hard drives using smart array 532 controller. The server is running Windows 2000 server. <BR /> <BR />If I add one more Hard drive to the existing RAID 5 system, do I need to re-install all software? Sun, 21 Jul 2002 23:00:00 GMT https://community.hpe.com/t5/disk-enclosures/rebuild-raid-5/m-p/2768614#M5533 Ayman Altounji 2002-07-21T23:00:00Z https://community.hpe.com/t5/disk-enclosures/rebuild-raid-5/m-p/2768615#M5534 No you do not. Please make sure that Dynamic Disks are enabled. Then you can expand your existing array. If it is not then you cannot do what you ask. I have attached a document which will show you what to expect. This is for NT but it is pretty much the same. Tue, 30 Jul 2002 23:00:00 GMT https://community.hpe.com/t5/disk-enclosures/rebuild-raid-5/m-p/2768615#M5534 Mark Cloutier 2002-07-30T23:00:00Z