By default the computer icon on your desktop or start menu is labelled ‘My Computer’. To amend so it reads username on computername, follow the instructions below:

1) Open registry editor
2) Locate KKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}
3) You should see a folder/key named LocalizedString with a value similar to @C:\WINDOWS\system32\shell32.dll,My Computer
4) The value type should be REG_EXPAND_SZ. If not delete the key and recreate giving it a value type of REG_EXPAND_SZ
5) In the value field type %UserName% on %ComputerName%
6) Exit from registry editor