OS in external harddrive is not recognised by my bios

Rinu Leo

Honorable
Mar 24, 2013
59
0
10,630
hello! folks!
straight to the point,
my computer was f'ed up last week.boot mgr is missing in my hard drive and what i did was installed a new OS into an external harddrive with my laptop by this process How To Install Windows 7 On USB Flash Drive or External Hard Drive and everyhting was good,installed the OS onto hardrive perfectly. but when i plug that to my PC it wasnt getting recognised,i mean it directly goes to installation ;[. and asks me to install it. i've set the first boot option to usb-fdd and restart and the same thing happens. i dont understand what to do now!! please gimme a solution about how to boot OS with the external hdd which has an OS installed and my harddrive as a storage,,
i've even tried by disconnecting the internal drive and just connected with the external drive!
it says DISK BOOT FAILURE,INSERT SYSTEM DISK AND PRESS ENTER
please answer me ASAP!!!!
 

Rinu Leo

Honorable
Mar 24, 2013
59
0
10,630

u sure there is no other way to get it recognised and use it as primary???