Changing user and computer name etc

My husband have given me his Sony Vaio Windows 8 toucn screen computer and bought himself a new one. I would like to change the logon, files etc to my own name and wonder if it is possible without formatting. IE10 does not remember my gmail name or password, nor facebook and other programs I use.
Any suggestions welcome.
Thanks

 

This is from Microsoft:


Try these steps and let us know the result.

- Press the Windows key and the X key and select Run.
- In the Run prompt, type compmgmt.msc and press enter.
- On the left pane, select Local Users and Groups. Double click on Users.
- Right click on summi_000 and rename it. <- (right click on the actual user name)
- In the Run prompt, type sysdm.cpl and press enter.
- In the computer name tab, select change.
- Enter the computer name that you desire and press ok.

Once you have made changes to the User account name as well as the Computer name, leave the Homegroup.

To leave a homegroup
- Open HomeGroup by swiping in from the right edge of the screen, tapping Settings (or if you're using a mouse, pointing to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Settings), tapping or clicking Change PC settings, and then tapping or clicking HomeGroup.

- Tap or click Leave.

- Restart the computer.

Once the computer restarts, try to join the Home Group and check if the name mentioned under homegroup has changed or not.

Go through http://windows.microsoft.com/en-in/windows-8/homegroup-from-start-to-finish

 

Thanks for the reply but I am a little wary of going into the workings of the computer having had disasters in the past, but I have been able to change the computer login name via the system page in Control Panel.