I need to format my c: drive and install a fresh copy of windows. Is backing up blocks as simple as copying the block folder to another drive and then put it back in? I really don't want to download 12 GB of data again... though in fact it used nearly 30 GB of internet traffic and ended up with 11.42 GB in total.
Yes, just copy and paste.
The only "important" file is the wallet.dat file which contains your address/keys, but all files can be freely moved.