Windows 7: Unable to make changes parental controls settings

I am logged in as the only administrator on my Home Premium laptop. I created an account as a standard user but i am unable to change its controls. It's kinda strange because it allowed me to change the time limits but when i try to set the "game ratings" or the "program limits" on, i get this message "...see your system administrator".
I then started the parental controls from the services but it didn't help.
I wasn't able to change it from my built-in administrator account either after i enabled it. So now i am freaked out it could be a serious problem?

Were all the steps followed as outlined in this tutorial?

Parental Controls - Setup and Use

If still no joy you could see if your computer has any damaged or corrupt system files that might be interfering with setting up parental controls. Run a system file checker scan from an elevated command prompt (option two.) If any problems are found, run the scan 3 times and immediately reboot the computer after each scan.

SFC /SCANNOW Command - System File Checker

It wouldn't hurt to also check for any malware that might be interfering. Run a full scan with your installed and updated anti-virus suite of choice. Since no anti-malware product is going to be 100% effective 100% of the time (if there was such a thing we'd all be using it) you could also run a couple of free on-demand scanners. The more scans that come back "no malware detected" the greater the probability that your computer is malware free. A couple of highly recommended free products are:

Malwarebytes

ESET Online Scanner

HitmanPro

SuperAntispyware

yes i tried all the steps in the first tutorial but it didn't help.
I also tried the second tutorial you suggested and after 3 scans i still got the same result that "no integrity violations", however i am still unable to change the parental controls settings for the account.
I had a full system scan just 3 days ago and my computer is protected.
What should i do now?

Disclaimer: I don't use Parental Controls so this is just a guess.

I believe that Parental Controls is a part of the Family Safety app in Windows Essentials.

Windows Essentials - Microsoft Windows

Under the old Windows Live (which I believe was replaced by Windows Essentials) it was possible to go into control panel > programs and features and uninstall individual components. You could see if this is still possible with Windows Essentials*. Uninstall the Family Safety app and then reinstall. It's possible that the app may have become damaged or corrupt and a fresh install may cure what ails it.

*In Windows Live there was a plus sign (+) in front of the main app. Clicking on the + would expand the app and reveal the individual components.

If this problem just recently started, you could also try rolling back your computer to an earlier date/time using System Restore.

System Restore

Hello, you were right in your guess. I uninstalled then re-installed windows essentials. It now gave me an option about setting parental controls using "Windows Live Family Safety" which to be honest i didn't notice if it was there before the installation.

Anyway i can change the settings now by my Microsoft account only, but the second option which is setting the provider to "none" and just trying to change the settings from the control panel still gives me that message.

I just want to add that i created another administrator account and another standard account and i tried to change the settings from the former to both the standard accounts that are presented now but it just won't let me.

I think I have had enough with these settings.
Thanks a lot.