Note that updating the bios and raid controller driver/firmware will not make a difference in regards to the ability to convert to raid 5 in your case; it's a limitation of the PERC series that you cannot grow your raid set if you put 2 or more virtual disks on it.
I have a PowerVault DP100 with PERC 5/i controller. It has one Virtual Disk with two logical partitions in Windows Storage Server 2003 Standard SP2 R2  x64 edition. It is configured as RAID 0 using all 3 physical disks (1TB each) .  I want to add an additional 1TB disk and convert to RAID 5 but rather not lose all the OS and programs installed on VD 0, I wouldn't mind losing all the rest of the data  on VD 1 as it will be replaced anyway. Is there a way to do this conversion without losing all the data and starting over? Ijust don't want to risk reinstalling that OS and all its drivers since I've never reinstalled a Windows Storage Server with Raid Controller before. Thanks for any help you may provide. Mary
PV DP100 - Convert from Raid 0 to Raid 5 possible without blowing it away and 
starting over?