common guys.... I have seen enuf of this..... "Switching to linux!!" . Reminds me of the good indian wife who always says "Main mayke jaa rahi hoon aur tumhare saath nahin rehna!" ... Very soon people realise the reality and are back with windows.
Windows is not bad, whats bad is how r you handling it. Win7 gives you plethora of security warnings but you want to keep the privacy settings to minimal coz you get disgusted by the repetitive prompts!! Well every high security installation in this world has multiple physical check points , so you should be ready to face similar steps in PC as well. IMHO security and convinience dont go along. Sacrifice one of them.
BTW if I was to steal any data from a PC it makes no difference to me whether it has win7 or linux installed. Moreover I dont even require to start the OS, leave apart knowing the password so security or privacy cannot be ensured with linux or windows. Remember the golden line
"Anything which is protected by 0 ans 1's can be opened by 0 and 1's", it may take small or long time depending on the persons knowledge, thats all.
Bottom line is know your house well to safeguard it, dont blame the mason if someone breaks in. In a chain there will be a link which will be the weakest, know it!!