Why can’t ‘SAVE AS’ anymore…?

I fiddled with my laptop a few weeks ago and changed some settings as I wasn’t able to upload a couple of mp3 tracks I bought online…it turns out that I just needed to use a different browser. Anyway…since then I can’t ‘save’ any thing to my laptop – whether it be Word or Excel or anything else really. If I open a document already saved on my laptop and want to rename it or something I can’t Save as either. I can’t undo what I changed as I don’t exactly know what I did!

Anyone got any suggestions on what I’ve done or what I can do?!

Thanx
Debi