Many thanks. I've tried F5 but it just continued to boot into Windows login screen. I'll try again, just in case - Not doing it - I've also tried holding Shift, Control and both together while pressing F5
In Windows XP Welcome Screen, simply press Ctrl + Alt + Del keys sequence together twice, and you will be shown a “Log On to Windows” menu which you can specify User Name and Password. In the User Name text box, key in Administrator and leave the Password field blank. Then press Enter or click on OK. If there is not password protects the Administrator account, or blank password is set, then you will be able to access the Windows with full administrative privileges as Administrator.