How could I fix this "Access Denied (policy_denied)" error?

I keep getting the following message whenever I try to access youtube.com:

"Access Denied (policy_denied)

Your system policy has denied access to the requested URL.

For assistance, contact your network support team. "

I'm using HP notebook, Windows XP, IE, Huawei Data modem.

I used to be able to access Youtube using my own dial-up network. I already called my Internet service provider, they don't see any problem from their end.

I may have created a glitch in my system when I tried to access the website in my office even though our office server blocks youtube, but I highly doubt that.

My content advisor is disabled, I've turned off all my firewalls, and even put youtube.com in all allowed lists that I can see in my browser settings.

Another major glitch is whenever I try to run command prompt, my computer automatically shuts down. I don't know if these two problems are related.

I've tried everything except system restore.

The "access denied" problem is sort of a common mystery problem with a lot of XP computers on WiFi connections. You did the right thing by checking your Content Advisor, but also check the Proxy Setting under the Connection tab, you don't want anything checked.

If your system is shutting down when you go to the Command Prompt that is a pretty major problem. I'm a pretty knowledgeable computer person and I rarely punk-out and tell people to format and reinstall. However, in your case, I would suggest that ... Before you do that, go to Google.com and search for: BleepingComputer + ComboFix , download the ComboFix program and run it, it's your last hope. If that doesn't work, then scrap your PC and do a fresh re-install.

I might need to know two things
- what is the internet settings on your comp?
- is there any proxy or firewall server running on your comp?

Check if you have firewall program running on your m/c? If yes then check the blocked site lists. Also run a full scan on computer with some good anti virus s/w and spyware removal utility too. Probably after that your problem will be resolved.

"I may have created a glitch in my system when I tried to access the website in my office even though our office server blocks youtube, but I highly doubt that."

I think that's your problem. Your PC might still be trying to access youtube through your work proxy server. Call your ISP again and ask for a new proxy server.

Run a scan with your anti-virus and your anti-spyware.Turn your firewall back on, never turn it off to try to get a program to work, it will cause you more problems.I think you have malware or a trojan messing things up.