If I am asking this in the wrong area, sorry

where would I ask this?
I have decided to delete calibre that I have present on my new computer. It has been switched from old to new, but I want to do some changes in how I set the books up (such as covers, almost half don't have any).
Also, working on the DRM aspect. NOT asking for help there.
So, I figure that if I delete current calibre and download from website I can fix the problems I caused when I downloaded (again, such as the covers, among a couple of others).
I have around 140 books, a couple that I bought, three or four are freebies but are no longer free (I would have to buy to replace them) and the rest from here and other free sites.
So, to make it short, can I save on my computer the books that are on my reader, in calibre, then when I install the new calibre can I add them back making the changes I want in calibre? I am gathering, naturally, that I have to delete them from my reader (Sony 900). Then, when I reinstall the books I can have them looking normal (instead of various sizes, no covers and such)?