Of course you can fix it, and this is exactly what you need: forget (reset) a password, normally, an admin password.
I hope you don't set up a password on access to the BIOS/EFI setup UI where you can change a boot sequence and boot from the CD/DVD or a USB drive (flash). If you have a password, I hope you did not forget it. If you forget that password, too, I hope you can find a manual for your mother board. The mother boards usually have a special socket with a couple of contacts you can shorted by a jumper. If you do it, your user-written non-volatile memory will be erased, bringing all BIOS/EFI settings to the default, in particular, disabling a password. When you do it, you run set up UI again and allow booting from CD/DVD or a USB drive. Anyway, most likely you already can boot from an alternative disk (I think so, because you mentioned reformatting the drive).
I also hope that your drive with OS is not encrypted. If it is encrypted, reformatting the OS drive is the only option.
This way, you can load another OS and get access to the drive where your system is. You should prepare some boot disk on some other computer, of course. The simplest thing you can do is to backup all your valuables and reinstall the OS, but your best option would be resetting a user password. As you are booted with the other OS, you can get yourself maximum privileges to your hard drive with your OS, so you can reset the admin password. Later on, you will boot up the usual way as the admin and change your user settings, too, and set up a new password.
Now, how to reset a password when you are booted with another OS? Oh, there are some rescue utilities to do that. Even though I rescue some systems from time to time, I don't remember which rescue disk I used to do the trick, but there is a number of tools. They are usually based on Linux or, more rarely, on Windows.
It looks like these two have this feature:
http://en.wikipedia.org/wiki/SystemRescueCD[
^],
http://en.wikipedia.org/wiki/Trinity_Rescue_Kit[
^].
If they won't work for you by some reason, you can find some other.
You can also try Hiren's boot CD:
http://en.wikipedia.org/wiki/Hiren%27s_BootCD[
^].
These tools (and many others) are free of charge.
Microsoft WinPE is also freely available:
http://en.wikipedia.org/wiki/WinPE[
^].
You will need to look throw the different tools and chose one which suits you the most:
http://en.wikipedia.org/wiki/List_of_data_recovery_software[
^].
[EDIT]
I finally found it, an important tool. It's YUMI, Multiboot USB Creator for Windows:
http://www.pendrivelinux.com/yumi-multiboot-usb-creator/[
^].
You can create a multiboot drive with a number of rescue disks from the pre-created list or add you own ISO's to it, so you can have a selection of bootable tools on one disk. Very useful.
Good luck,
—SA