Cant log on as Administrartor & Main User.

[NormandeBarra]

On our family laptop, i am the administrator and one of 2 users. When i try to log on, the following message appears
"The user profile service failed the login.User profile cannot be loaded"
When i try to solve issue i am asked repeatedly for my password, which when input is not accepted. As i have little experience with Computers, i am lost on how to proceed.
Any advice would be appreciated.

[Geek-9pm]

Welcome to the CH forum.
Without more details, it is hard to give an exact answer.
Can yoo provide information about then make and model of your laptop?
What operating system do you have?
Have other family members made administrative changes to the computer? What did they do?
Have you tried Safe Mode?

Do you have the printed documentation for the laptop?

[NormandeBarra]

Thank you for your welcome and help.
The Model is a Dell Inspiron April 2009. The system is  Windows Vista, Home premium.
The only other users are 2 Teenagers who would not have had access to my user password and therefore dont think they altered anything. i did not make any changes from last exit to attempted logon.
As to safe mode, i cant gain access under my account as it is password protected. If their is a way to gain access via "safe mode" i would welcome direction.
Again, thanks for your help.

[NormandeBarra]

Additionally, i tried to log on by resetting my password. This was not successful. The following message appeared
"this feature requires removeable media, such as a floppy disk or USB flash drive. Please insert floppy disk or connect USB flash drive, and then try again." 

[Geek-9pm]

To enter Windows 7 Safe Mode, you must log on with an account that has administrator permissions.

How To Find the Administrator Password in Windows 7