"Missing operating system" massage is coming when i start my system. I think because , i had given "mark partition as active" option for one hard dive (E) in disk management when last time i opened. it did not have any data. i did not know, this will make any problem. Now i am not able to boot windows re installation dvd also. i can only take BIOS settings. please any one suggest any way for rectifying this problem ASAP.
Try this: Disconnect the E drive and leave only the c HDD and your cd/dvd drive connected. Now go into the bios and make sure that the cd drive is the first in the boot order. This should let you boot from the cd/dvd drive when the Win. disk is in. Try to boot first with no disk in as it may find your operating system on the c drive. Once win is up and running you can re connect the other drive. Once detected you can format it or whatever you want.