Windows 7: changed boot priority now cant change it back

hello,new guy here.i resently ran a memtest86 program to check my ram so i had to change my boot priority to get the program to work.now it seems i cant change it back.ive changed it and saved it but my cdrom still wants to boot up first.i even reset the bios with no luck.can someone help me out.

When entering bios you should be able to access the boot menu and select which device to boot 1st/2nd/3rd, after making any changes you must select to save & exit normally F10 key

Having dvd/cd first is quite normal followed by your OS HDD

yes i did all that but it still tries to start the cd rom first i can hear and see it trying to start 2-3 times and then Windows 7 starts

What have you selected as first boot device ?
How many HDDs are in your machine

i only have one hd.its set to removable de or whatever that is,hd,then cdrom.like i say i reset the bios settings which put it back to what it was before i changed it yesterday.

The disk drive activity light always comes on when you power up thats normal and if there is a disc in the drive the machine will always spin up the disc when powering up even when not booting from it

theres no disk in the drive.i wonder why it tries 2-3 times before the os starts?never did that before until i changed it yesterday the issue ive tried to figure out is why my system randomly reboots.it may run for days or my only reboot once in a day.doesnt seem to matter what im doing but it never does it while im playing games.them i look at the event logs and it says critical error,someyhing about kernal-system or something,where can i find those dumpfiles or something

anyone?

It's probably trying to find the removable drive. Sounds like you may have set the boot sequence incorrectly. There may also be a boot priority option that got reset besides the boot sequence. Re-check all boot options carefully. You may also have to select Advanced Option to see all the boot options.

what if i reflash the bios?would that fix it?