this thread will never end
but, as a 'old boy' wich started his computer life on a spectrum zx1, c64, atari, amiga to dos 3.11 till windows 7 now... there is just one thing you have to learn with microsoft - MAKE FROM YOUR RUNNING SYSTEM A BACKUP and put all your important data on a second hd, dvd and/or nas.
try new software not at home, go with a usb-stick to a friend, maybe not to your best one *LOL*, and try it there or go in a internet cafe... or try it on a virtual pc - and you have no problems at all!
ohh, and of course... don't forget to save your registry... at least once a day...
and if you deinstall a programm... see in the drawer 'common files' to... and in the appdata drawer under local and... and clean the registry at least twice...
did i say that you should make a backup before you deinstall a programm?
hmm... is there anything else or did i forgot something?
oh yea, as i'm swiss-german (Grüezi zäme!), my english is not ferry goot, sorrz
have a nice day!