After renaming my PC, I don't have access to my files and/or applications. I tried to give access to myself via computer/properties/security but I am not allow to access this either, and I don't have access to user account.. Can someone help?

Do you have XP Pro? Before renaming, was your computer part of a domain? If so, renaming would remove your machine from the domain, cancel any any logins based from that domain, and any authentications based on that domain would be void. Very possibly, you can no longer log into your own machine unless you have created a local admin login account on the machine:"You cannot log on after you remove the computer from the domain" < http://support.microsoft.com/kb/317049 >Of course I've made quite a few assumptions but the symptoms all seem to fit. It would help to know if you have administrative privilege. The quick way to tell is to right-click on "Start". If one of the choices in the pop-up window is "Open All Users", then you do have admin privilege, else you don't.HTH, JW

JW,You certainly know your stuff! I have XP Pro, this PC was part of a domain at one point, and I am allowed to login to the computer (I do have admin privileges) but does not allow me to change access rights. Can you suggest what to do?Thank you,SR

SR,This may not be as bad as I first thought. It depends on what you meant by "I tried to give access to myself via computer/properties/security but I am not allow to access this either". Assuming what you meant by this is that the "Security" tab is missing, then the problem is likely that "Simple File Sharing" is enabled. You must disable Simple File Sharing to gain access to this tab. See:"How to disable simple file sharing and how to set permissions on a shared folder in Windows XP" < http://support.microsoft.com/kb/307874 >and if you get access to this tab, you might be able to perform the following which will switch ownership of folders back to you:"How to take ownership of a file or a folder in Windows XP" < http://support.microsoft.com/kb/308421 >If, on the other hand, the tab is there but won't let you change anything, you might see if you can use System Restore to revert your machine back to before you changed the computer name..."How to restore Windows XP to a previous state" < http://support.microsoft.com/kb/306084 >HTH, JW

Hello JW,I disable simple sharing and I took ownership of all folders, but the problem still persist. When I try to change my computer properties I am denied access completely. I am denied access to system restore as well. Any other ideas?

This is odd. It seems like you have administrator privilege but you are also excluded from normal administrator functions.Try creating a new user on your machine and give that user Administrator privilege. Then try logging in as that new user and see if you have the same problems. If you cant get permissions to the User Control Panel, then see if you can bring up a command prompt (Start -> Run -> "cmd") and add the user manually by entering the following commands (this will create a user called "Adam" with password "password"... net user adam password /add net localgroup administrators adam /addHTH, JW

I tried running the command prompt, but it does not allow me to run "cmd"!I was able to run system restore running windows in safe mode, I got my computer back. Thanks for your help.

I'm glad you were able to figure it out and recover your computer.Thanks for the feedback.-- JW