Hi, sometimes Windows goes to a stall process when i login, i press Ctrl+Alt Del and do the login process again and everything is fine.

I shall suggest you go through the workarounds as suggested in the following thread:

http://answers.microsoft.com/en-us/windows/forum/windows8_1-performance/windows-81-hangs-on-please-wait-screen/fb09be8c-8297-4660-bfe6-845eab394e9d

Hello Filinto Rodrigues,

Do you mean that the system freezes in the startup process?

Please use the Windows 8 startup repair to fix the problems that keep Windows from loading.
For more information about Startup Repair, please take a look at the following article.
http://www.eightforums.com/tutorials/4924-advanced-startup-settings-boot-windows-8-a.html

Please note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

Please open the event viewer and check if there are any related error log. For more information about the event log, please refer to the following article.
http://windows.microsoft.com/en-us/windows/open-event-viewer#1TC=windows-7

Best regards,
Fangzhou CHEN