I'm assuming that you're using a Microsoft-based email account. (i.e. with an address that ends in @outlook.com or @hotmail.com). If you're using a different account then, obviously, resetting your Microsoft password isn't going to help!
The Microsoft 'lost password' site is here:
https://account.live.com/password/reset
However, even if you can get back into your account, you need to think about what someone who's had access to it could have done while he was there. For example, he could have looked through all of your emails to see if there's anything there which would help him to gain access to your bank account (or, for example, your Amazon account). Further, he could have copied all of your contact details, so that he can then send spoof emails to all of your friends, pretending to be you and inviting them to click on the links that he includes in those emails. He'll still be able to do that even after you've reclaimed the account for your own use. (I once emailed another AB member, so that my email address ended up in his contacts list. He later had his account hacked and, even though he can now access it normally again, I still get fake emails purporting to come from him once every few months).
Remember also that if you've used your email password for anything else (such as to access your Amazon account), the hacker is likely to try accessing any other accounts that share the same password.