I hope I'm not to late for a little help/advice... I've got a HP/Compaq 6820s (ICH8) with HDD and DVD drive. I bought a DVD Caddy but it doesn't "see" the SDD, so I replaced the HDD for the SDD (/dev/hdb) and the DVD for the HDD + DVD Caddy (/dev/hda). I was using Windows 7 + UDMA_fix software workaround, but Windows 7 was freezing every other boot, sometimes more. I decided to move on to Windows 8.1 update. SDD is working in UDMA5 (hdparm.exe -t /dev/hdb reports 237.33MB/s) and the HDD is back to MDMA2 (hdparm.exe -t /dev/hda reports 13.95MB/s) but I don't want to use UDMA_fix again. Does the MBR method for Windows 7 still apply to Windows 8.1? Is there another alternative, like modding the BIOS to make it accept 2 HDD instead of forcing HDD + DVD (MDMA2)? EDIT: Just replaced the MBR with the patched one from tiuser and it worked great! hdparm.exe -t /dev/hda now reports around 65MB/s for the HDD! My OS is Windows 8.1 Update Pro 64bit, I used Hirens BootCD 15.2 to boot with MiniXP, them I used the included Hex Editor HxD to back up the 1st 422 bytes of my MBR and also the full 512 bytes to a pen drive just in case, then copy/pasted the patched MBR in its place. Just make sure you're selecting the right drive, HxD just lists them as physical disk 1, 2, 3, etc with no extra information, so I opened each one in read-only mode, changed hex to decimal and checked the end of the disk to see what was its size. Since I have a 120GB SSD and a 320GB HDD, finding the SSD was a no brainer.