|Will it let you log on in safe mode? (keep tapping F8 key before windows starts to load)|
Could be corrupted profile - but odd if both you and your wife affected at same time. Could be malware or just corrupt system file (though usually you'd get a blue screen in this case). If its malware it may well start in safe mode - in which case something like autoruns (or built in msconfig) would help identify likely cause from startup list.