I'm running Windows 2008 Server R2 on my Dell Poweredge. I've got a Perc300 controller and 3 WD500 RE4 in a RAID 5 array. I just had drive 1 fail. I know that it's a good rule of thumb to replace the other hard drives too as they may be failing soon. The server and drives are about 5 years old. I needed to get the server online and the only drive I had available for temporary replacement was a WD 1TB Red drive. I've installed this drive and successfully rebuilt the RAID5 array. I'm not comfortable leaving this drive in for long and I'd like to put back the WD500 RE4 drives. So, I've ordered 3 WD500 RE4s to replace all three of the drives. What's the best way to do this? I was thinking that I needed to remove one drive at a time and perform a rebuild on that drive. When that's done, I'll take out the next drive, perform a rebuild. Then finally I'll remove the third drive, replace it and then do another rebuild. This server is in service 7 am to 8 pm 6 days a week so I don't have enough down time during a normal day to take down the server for hours at a time so that's why I was thinking about this solution. Will this work or is there a better way to get this done? Thanks for your help!