Does anybody knows how  to recover forgotten password for Windows 8.1? I forgot the password and can't access it, need help! 

This is a CAD help forum not a Windows help forum.So, what you are saying is you can't boot into Windows because you decided to use a password upon boot up and you forgot the password.  Is that right?  This has nothing to do with trying to open a password protected drawing right?

Sorry, but really I need to reset my windows password, I think guys in this forms can help me!  

How difficult would it be to search the Microsoft website for advice on resetting a password?  Answer: Not difficult at all.http://windows.microsoft.com/en-us/windows/what-do-forget-windows-password#1TC=windows-7Did you create a reset disk or USB?  I'm betting that you didn't.
John Connor2016-01-04 11:47:48

[QUOTE=John Connor]How difficult would it be to search the Microsoft website for advice on resetting a password?  Answer: Not difficult at all.http://windows.microsoft.com/en-us/windows/what-do-forget-windows-password#1TC=windows-7Did you create a reset disk or USB?  I'm betting that you didn't.
[/QUOTE]
It’s not an easy job people who don’t have much knowledge in computers. however, most of the users are advanced users with computer, so bear in mind with that.

If the OP could find this site then he could surely find Microsoft's website don't you think?How many times in a week, a month or a year, in print, on TV, radio or on the Internet have you heard the word "Microsoft"?  Now, given the same criteria, how many times have you heard someone refer to the CADForum?If computer users do not know how to do a search of the Internet maybe they should learn.  They should also learn to write down passwords so as not to lock themselves out of their own computer or file.  Live and learn though isn't that what they say?
John Connor2016-01-06 11:46:49

OP, did you get you password back? if not, then check this tutorial out. It's quite simple and I did a test on my Win 7 computer, it worked: http://www.iseepassword.com/how-to-reset-windows-7-password.html
donaldssp2016-01-10 03:02:47

Before I would click on a link to a website like the above I'd visit the Microsoft website.  The articles found there typical contain links to other related articles all written by employees of MS.  The information can be trusted.

Boot off Windows install DVD and you can reset the lost password from Command Prompt:http://www.howtogeek.com/96630/how-to-reset-your-forgotten-windows-password-the-easy-way/http://www.top-password.com/knowledge/reset-windows-10-password-without-reset-disk.htmlNo need to use any untrusted third-party software.

above all the settings windows password reset screen appears.Select the Windows system type and the account you want to reset its password, and click "Reset Password". ...Click Reboot to restart your computer, then you could login Windows 8 without password successfully.