I will refer you to the following article from Microsoft regarding this issue: How to take ownership of a file or folder in Windows XP
I have assumed that your new machine has XP - if it is running something else, please correct me.
As long as you are able to log on with an account with Administrative privileges, you will be able to replace the current access restrictions on the folder and/or files within.
If this does not solve your problem then the solution is a little more tricky. Let me know if that is of any use and if not, I will try and find out what the problem is - the majority of problems such as yours can be solved in this way, though I am assuming that it is purely a Windows permissions error and nothing more sinister.