When I go into my HP Array Configuration Utility, there is no errors and and warnings. No visible amber lights either. Should I swap out the disks? This Windows server lost the storage about 4 times this week.
I recommend that you search for more information about this error before you start replacing any hdd's.
Info from HP support site about this: http://h30499.www3.hp.com/t5/ProLiant-Servers-ML-DL-SL/hard-drive-error-640006-on-ML350G5/td-p/5597711#.UGQfJFEv-J8
If you don't care about the cost of replacing the disks, replace them as soon as you can. You could always do the diagnostics of the disks on a second test server later, just to determine if your disk actually are bad or if it's the HPID Tool that is reporting false positives.