Good point: Is your 2008 R2 ISO SP1?

Which RAID controller do you have?

What make/model of drives are you using? What size?

Boot Mode set to BIOS or UEFI?

Hello

It would help to know how exactly you are performing the installation and what step it is failing.

If it is making it through several steps of installation then it is likely a software compatibility issue with the OS or a driver. Review the operating system support matrix to make sure you have the necessary service pack for 2008R2, if required.

https://www.dell.com/support/contents/article/product-support/self-support-knowledgebase/enterprise-resource-center/server-operating-system-support

If that is not the issue then remove any hardware that has been added to the system, PCIe, USB.

Thanks

yes its a 2008 r2 iso sp1 

i have 3 raids configured on the server, in which i tried booting from all 3 and none work.

i have two Raid 1s , a 300gb and a 600gb 

and i have a Raid 5 in with 2 TB

when booting from USB i have two options once im in the UEFI boot menu , boot from BIOS or Boot through UEFI 

in which i click on UEFI to boot from. 

All help would be appreciated . i tried multiple bootable USBs with several different OS to test and none seem to pass the "Finishing up portion of the OS installation".

sometimes the installation doesnt even start i get the error message "windows installation encountered an unexpected error. Verify the installation sources are accessible, restart the installation"

error code: 0x0000005