it required some number for activating. it goes like this xxxxx-xxxxx-xxxxx-xxxx-xxxxx-xxxxx. and i am just confused what kind of numeral should i fill into the box
The number is called the 'Product Key'. It is required in order to activate Windows. If you do not have this number, no one here can tell you any numbers to fill into the box.
Your number is specifically intended to be used for your copy of the Windows operating system. It is not intended to be used with any other copy of the Windows operating system, nor is the Product Key for any other copy of Windows intended to be used with your copy of Windows.
You may try looking on the computer case to see if there is a small sticker which has your Product Key on it. Some computers have this, others don't
someone installed mostly the softwares for me.
If you cannot find, or do not have the Product Key for your operating system you may want to contact that someone who installed your software to see if they can give it to you.
Otherwise, as far as I know, you have 2 choices;
You can either request a replacement product key from Microsoft or you can purchase a brand new copy of Windows.