File extensions not visible

On my XP Laptop i can't see any file extension with any of the file. When i go and clear "Hide extension for known file types" under Folder options then it does not stay permanent and i can't see file extensions.

Is there any registry settings i need to check or change? thanks
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Value name   : HideFileExt
Possible Data : 1 or 0
You have been infected with a virus. Run something like hijackthis to figure out what's running on your computer and perhaps it'll even fix it for you.
I would also run malware removal tools as I agree with wellhole this sounds like a virus.

A few good ones are malwarebytes, SUPERAntispyware, and you should run ccleaner as well.
tech2010Author Commented:
superqqq: after change registry value to 0 it fixed the issue. I wonder how it happened. Could there be virus on my system? will it now stay permanent?
It is possible that it's a virus.
Do the following:
1.  Update your virus scanner and then run a full system scan.  
2. Run windows update.  You may have to do this multiple times until there are no more updates available.
If you are on a domain then a group policy may be changing the value.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
System Utilities

From novice to tech pro — start learning today.