Is Wrong Password a virus?

I wish you all have a wonderful weekend!

I have a windows 7 computer (Lenovo) with two users.
One user is mine (the one with password and the user I can have access to download or update anything that I want to).
The second user is my little boy that uses for games.

For while I can't log in in my user. I never have changed the user's password either my son has done it because he never knew my password.

Problem is my user indicate all the time that my password is WRONG and when I try to change it (the user requires a USB drive. I bought a drive and my computer insists that I have the wrong drive on it and I can't change my password.

I have all my work documents, my personal documents and much more in my computer and I just can't have access to this and my sons user can't be download anything without my user permission.
I can't give the permission because my user doesn't accept my password.
I'm hesitant to bring my laptop to a computer repair store since I heard too many times that computer stores can change your computer pieces, they can take your new pieces and put others old and we never will know until eventually later your computer breaks down and you can't prove anything. Also I don't make enough money in my work to use it to repair my computer.
My computer is about 1 year old and I fear pieces being exchanged in a computer store.
Someone please would know how to fix this password thing?

I really appreciate your help if you can help

Usually wrong password means just that. I'm old and shaky. Sometimes I have to put my password in at least
three times, and I think I'm putting the same one in each time. If there's no other way for you get into your computer
I guess your only choice will be to restore your computer back to factory settings. Then of course unless you can get on some way and save your most important files and programs to some storage device you will lose everything that is on the hard drive.

I think your password has been changed! If not try a windows DVD and copy all the files through CMD and try reinstalling the windows!

If I were in your position I would do a clean install of Windows and then restore all my files from my backup device, but I'm guessing that you don't have your files backed up!

Some years ago a friend had a computer that was playing up; I bought a bootable recovery CD/DVD from Spotmau and used it to rescue a computer that wouldn't boot up. I think I'd try it again, and try to use it to copy my files from the hard disc to a separate device, then do a clean windows install.

Once the computer is recovered, I'd immediately put a backup strategy in place!

(Before buying a recovery CD/DVD from any company - I'd phone their customer services to check that it will do what you want - copy files from your particular laptop onto a separate USB device)

More specific please