Ownership of a Folder Issue after XP reinstall

I have a partitioned hard drive that has all of my photos, videos, ect on it. I check the encryption box under properties and gave ownership to my username.

I recently reloaded a fresh copy of windows xp/media center edition. I have access to everything in my partition except for this folder. Instead of the owner being my username, it's now listed as ? S-1-5-21-1659004503-436374069-1801674531-1003. I know this is a SID.

I have tried taking ownership of this normally and by logging into safe mode. I can take ownership but when I log back on. I can't play the videos and I can't open the jpegs. When looking at the files in thumbnail or filmstrip view, I can see the pictures but above it says, "no preview available" and the videos even though I can see what they are, won't play and say that I may not have access to the computer or my proxy settings are incorrect. Basically, I can't open any of these files. Does anyone know how to get ownership back either using a recovery program or Linux?