Spoon, You are not alone my friend. I have exhausted all possibilities. After trying all of the suggestions here, and multiple E6220's, and multiple usb drives, in multiple ports, I am all out of hope for this one. I know that all of my drives and ports on all of the system cannot be bad. I also use the same media to install ML 10.8 on multiple E6420's with no problem. I have four different Brand USB's that have be re-installed multiple times. CONCLUSION: There does appear to be an issue with getting this setup on an E6220. Mainly the error on first boot when trying to begin the OSX installation. EBIOS read error: Controller or device error Block 0x1d0978 Sectors 0 EBIOS read error: Controller or device error Block 0x1d0978 Sectors 0 EBIOS read error: Controller or device error Block 0x1d0978 Sectors 0 EBIOS read error: Controller or device error Block 0x1d0978 Sectors 0 I get the same on 320 - 5400 HDD, 1TB - 7200 HDD, and 128 - SSD HDD, So I know it is not drive related. I can install with the same USB and HDD that give error, if I remove them from E6220, and place them into an E6420. Specs: E6220 (BIOS:A10 - On First PC/ A8 - Second PC / A3 - Third PC), i5-2.5GHz, 4GB, Intel HD 3000, 320 GB HDD, WiFi: ASUS USB-N10 Any Further Help would be greatly appreciated.