Are you able to access it through Command prompt?
Otherwise, there are a few options, and I'll recommend them in order.
1: If accessable through command prompt, try to copy and paste to another location
2: If not, or if the problem persists after successfully completing step 1, you may want to engage permissions for the user group "Everyone" for that folder and all sub folders
3: CHKDSK performed with the proper modifiers for continuation upon restart
4: XP Repair Console, and see if you can move the folder to another location/verify integrity of the files inside
Be careful in XPRC, as poking around with the wrong things can brick the OS Install