I have windows 7 in disk C and windows 8.1 in disk E, the access to each one I do from Bios quick menu where I select the disk to boot. While I am executing windows 7 all times and exit it ALL is working perfect, but if I enter Windows 8.1 all also work ok while I am there, but when I quit the Windows 8 and try to enter Windows 7 always the CHKDSK shows the message that one disk may have some incoherences and need to be checked, If I let the chkdsk work it do not find any problem. Now windows 7 will work perfect every time I enter till I try to execute the Windows 8 again, then the CHKDSK come again with its message (I observed that windows 8 convert the disk E in disk C for their session and to the phisic first disk gives the letter E). Any user can know why this happen?, and principally how to set? Thank you in advance.