Trying to so a 'clean install'. Now "missing operating system"

Sasha100 said:

Thanks for all the suggestions everyone. I can get to BIOS by pressing F12 (or F2) at startup. I then go to the BOOT menu, select CD/DVD drive and exit with"saving changes". Reboot and - nothing. I will try using the 'BOOT Disk' I burned in my desktop and get back to you in a few minutes. Thanks again.

You don't want to change boot device setup in the BIOS, you need the 'boot once' menu at Startup.
Press Esc when you see the Dell splash screen.

I tried the 'BOOT' disk in my Desktop and it work fine. The problem in my Laptop continues. Reading the posts by "Ztruker" and "Edwin" I believe the 'recovery data' was deleted as I zapped all the partitions except the 'OS' partition. By the way, I tried rebooting my Laptop with my Win 7 disk - not luck with either. The Laptop Bios will not accept the change from "hard Drive' to 'CD/DVD Drive', (and I do exit with 'save changes'. Ztruker: To answer the question about where did I get the 'BOOT' disk, I created it from the Killdisk download. I have the Win 10 ISO from the download from Microsoft to get the Win 10 on my machine. I guess I should have just done the Win 10 update and not tried to get fancy with a 'clean install'. Anybody got any suggestions how to get the use of my Laptop back?

Thanks again for all the suggestions. This is what I have done so far -
1) I made a DVD "Boot" disk on my HP Desktop from the downloads from Killdisk. I tried it on on Desktop by changing the BIOS startup and it worked. My Dell Laptop seems that it will not hold a BIOS change. I start the Laptop and press F12 (or F2) and change the Bios startup from hard drive to CD/DVD drive , exit and save with changes. But it doesn't want to recognize the change and the message 'missing operating system' appears yet again.

2) I tried using my original Win 7 installation, but it won't work either. I believe the same issue applies - the BIOS change is not getting recognized.

3)The only Keys that will give me anything are F2 and F12, will take me to setup.

4) I think the 'Recover Data' got zapped when I used Killdisk to wipe all partitions except the "OS" partition. But something must have deleted the BootMgr files or ??

5) Any ideas folks? Thanks for your time already. What is my worst case scenario here?