error logging in..windows 10

[WPCentral Question]

i bought a new laptop here in japan with windows 8.1...so as expected my laptop is in japanese, even the keyboard layout is different. at first logging into my account was not a problem, until i downloaded a language pack to change it into english, i met a problem. whenever i log in i keep recieving this error message "That password is incorrect. make sure you're using the password for your Microsoft account. You can reset it at account.live.com/password/reset"...i've already changed my password on the said site but the message still appears. but when i restart my computer the error message will not appear and i can get into my account. even after i upgraded it into windows 10 the problem is still the same. please help...i'm kind of scared to troubleshoot it my own because this is my first time using windows 8.1/10 so i'm not familiar with the settings and all, even though i've successfully changed the language into english, the settings are still in japanese...