Most likely if you are moving your address book from your old computer you were using Outlook Express. These directions will be for moving form Outlook Express to Windows Live Mail. In Windows Vista Microsoft replaced Outlook Express with Windows Mail and in Windows 7 the program became Windows Live Mail.
You will first export the address book from Outlook Express on the old PC. Open the program then choose Export on the File menu. Choose to export as a Comma Separated Value(CSV) file. Remember what you name it and where you save it. Then put the file on a flash/thumb/usb drive and move the drive to the new PC.
Now on the new PC make sure you have plugged in the flash/thumb/usb drive. Now start Windows Live Mail (it is on Start menu in Windows 7) and choose Contacts near the bottom left side. Now choose Import on the ribbon with the icons, near the middle. Choose Comma Separated Values (CSV). You will then locate the file on your flash/thumb/usb drive in the Browse window and click next. Choose the fields you want to import (first name, last name and nickname are important) and click Finish.
Your address book is now on the new computer in your new email program and you can easily write all your usual contacts.
Thanks Mary for the question