UEFI Boot Problem with Windows Server 2008

Hi,

I have been running a PowerEdge R510 with PERC H700 Controller and 4 x 1TB SATA Hard Drives (RAID 5) for about 4 years. I have just rebooted the server and now it cannot boot up into Windows.

I can see the Virtual disk of 3TB on the RAID Controller configuration and when using the UEFI Boot Manager all I can see is the options for DVD Drive and NIC/PXE Boot. It seems to have just 'forgotten' about the disk array.

I cannot see any hardware failures or other problems prior to reboot and simply cannot access the disks. It simply just looks like the UEFI cannot see the disks. Hence why it cannot boot into Windows.

Please can anyone kindly assist? Thanks

Alpesh