Booted wrong device

[Minimans]

I have a dell inspiron and i tried to reboot/format what ever you want to say to clean the files but as in the title i booted the wrong device by pressing f8 on startup i didnt mean to press devices but i did but when i tried to press back i pressed a random usb device and so my pc doesnt know how to react so it tries to boot up fails and restarts and i have no windows disks and other stuff like that so i wanna know how to revert what i did

 

[tman1]

Reboot - restarting your machine, like hitting a reset button or turning it off and on again.
Format - basically wiping a drive.

Pressing F8 during or after POST brings up a windows boot menu, giving you options such as safe mode, safe mode with networking, last known good configuration...

Nothing you could have selected at that menu would have messed anything up.

So you need to be specific with what you did, otherwise we would just be grasping at straws.

 

[Chicano]

Ways to reset the Windows boot device:

1. Remove the USB device from the port before starting the computer
2. Enter the BIOS and reset the HDD as the first boot device
3. Reset the BIOS with battery removed for 5 minutes or with the BIOS reset jumper moved from pins 1 & 2 to 2 & (previously remove the AC power in both reset methods)


EDIT:
That seemed to me the problem initially but now that I read carefully, I have a few questions:
1. You tried to format reboot and format?... but you don't have a Windows disk (or other stuff) so how did you plan to format and start a fresh installation, or did you just want to use the HDD for storage?

2. If Windows starts to boot and restarts, without a Windows installation disk or USB, your only option is to logon in Safe Mode, pressing F8 right after the BIOS finishes posting and you hear the beep... from the Safe Mode list of options select Safe Mode or Safe Mode with Networking and press Enter. In Safe Mode, Restore the System to revert what ever issue you may have caused.

3. In Safe Mode, install EasyBCD to repair the Windows bootloader.