When you say "it prompts me to browse file explorer for drivers", what exactly is the message you are getting?  As Geoff said, the drivers should be native to 2012 as well.  Depending on the message you are receiving, you may have bad media (download, burn, etc.). Did you Initialize the RAID array when you configured it? BTW ... you should always update the ESM/BMC with the BIOS.
I have an old PE2950 I'd like to put Window Server 2012 on.  When I enter in my service tag (xxxxxxx ) I don't see an option to download drivers for PERC 5/i.  Can someone link me to the proper drivers? Thanks!
Window Server 2012 on PE2950