Helping people with computers... one answer at a time.
Web services often log activities and usage information. Exactly how much is logged and what it takes to access the logs is typically not known.
Does MSN Hotmail (now Windows Live Hotmail) keep a log of when and from what specific computer I logged into Hotmail? I think someone is accessing my mail as this particular person keeps turning up to things I am at. He is a little strange but I don't want to inform the police until i know if he can be traced.
Short answer: we don't know.
The longer answer is that there may well be logs, but whether they contain what you need, how long they'll be kept, and what it takes to even get the answer are huge unknowns.
It's pretty easy for any web-based service to keep logs of its activity. As we've discussed before, web servers at a minimum typically log the date, time, and IP address of the requesting computer every time a web page is visited. More complex applications may well log additional information like the account name that logged in or other specific activities that the web service performed.
The problem is that we just don't know what information Windows Live Hotmail keeps in its logs. Microsoft won't tell you.
Another problem is that the information they do log may not be enough for what you need. As we've also discussed repeatedly, an IP address is not enough to identify a specific computer or user. Even if you were able to get the IP address associated with your last login you might get close, but it's also quite possible you won't get nearly close enough for that to be useful.
Yet another problem is the sheer volume of information that those logs might collect. Windows Live Hotmail has millions upon millions of accesses every day. Logs that include any useful amount about those accesses would be huge. Too huge. So as a result it's extremely likely that even if there are logs, they're only kept for so long before they're discarded to make room.
How long are logs kept? Your guess is as good as mine. A day? A week? A month? Longer? There's no way to know. Microsoft's not saying.
Finally, let's say the information you need is being logged, and it's being kept long enough for it to still be available. What then?
Microsoft will most certainly not just give it to you if you ask. Besides being a huge privacy risk, it would require more resources that Microsoft just doesn't have allocated to what is a free service. You get what you pay for and you're paying nothing.
Chances are the police can't just walk in and ask for it either, though I suppose it's possible. More likely is that the police or other law enforcement officials will have to go to court and get a court order forcing Microsoft to release the information they have.
It sounds like it's quite an ordeal to get this information, and it needs to be. You don't want this information to be freely or easily available for privacy reasons. Making it difficult helps protect every Windows Live Hotmail user's privacy.
The bottom line is that only law enforcement can tell you whether or not they can even try to get the information based on just how serious the issue you're facing is.