Can’t view thumnails

I am running Windows XP. My pictures (mostly in Jpeg) are in my pictures folder in my documents and in that folder i have lots of subfolders etc… those folders have thumnail images on them which i can see but the second i click that folder i cant see any thumnails. I can’t view any thumbnails on my computer!

I have been on infopackets.com and found an article ‘can’t view thumbnails’ and the solutionn was
All that you need to do is click Start -> run, and type in:

REGSVR32 SHMEDIA.DLL [and click ok].

I tried this and it hasn’t worked. Also, I am running an original Windows XP – but lost the CD! I think it may be a regestry error but not too sure. Please help!