Change the Boot order or get into the BIOS.
What is the exact model number? Toshiba does not list the 8600 as belonging to the Tecra line (unless it was hiding in the archived section).
From the Toshiba support site;
This bulletin documents the several different methods for gaining access to the BIOS Setup feature of most models of Toshiba computers. These setting are stored in non-volatile CMOS memory, hence the alternative term "CMOS Setup". The settings are managed by a utility program built into the computer's BIOS (Basic Input/Output System).
For Toshiba desktop PCs and servers : Press and hold the F2 key immediately after turning the computer on (during the Power-on Self Test (POST)).
For Toshiba notebook PCs manufactured since the introduction of Windows XP, one or more of the following methods will be effective:
Toshiba Hardware utility method: Run the Toshiba Hardware utility from the Toshiba Console. It may also accessible (as 'HWSetup') from the Windows Control Panel. Changes to some of the settings will require re-starting the computer. This method is the only way to access the BIOS settings on some notebook PCs (Satellite 5000 series, for example). (For these machines, pressing and holding the F12 key immediately after powering-on the notebook will allow you to alter the notebook's boot priority.)
If the Toshiba Hardware utility is not present, try the F2 key method and the Esc key method (see below). The Toshiba Hardware utility may be downloaded from the Toshiba support website at http://support.toshiba.com
If the computer is fully off, and/or to avoid having to re-start it (and Windows), use one or the other of the following two methods. The PC will have to be truly off (not suspended, or in standby mode, or in hibernation mode). If an external keyboard is attached to the notebook (either directly or via a docking station or a port-replicator), disconnect it until you have completed this procedure.
F2 key method: Turn the computer on. If you see an invitation to press the F2 key to enter Setup, do so. The Setup screen will appear.
Esc key method: Turn the computer on. If you do not see a prompt to press the F2 key, then immediately press and hold the Esc key for three seconds, and then release it. When prompted to, press the F1 key. The Setup screen will appear.