I would persevere a little before taking to a shop, as their Normal response to this type of problem is to either wipe and reinstall or replace the HDD and reinstall. both of these options are the easiest for the shop and also the more expensive option for you

- it will also likely delete your data on the drive
Check any documentation you have to confirm the key to enter the bios is F2, you can go to the Toshiba site and confirm this for your actual model.
As to actually, invoking the bios setup, as soon as the system starts, you should hear a single beep, tap the key immediately you hear the beep and keep tapping every half second/second or so It may take more than a few tries to get this right. once into the Bios it's normally fairly simple to set the boot drive.
You can also try a startup/boot repair from the original windows disk as explained in
this tutorial
Another option is a disk manager such as the free Partition Magic
Best Free Partition Manager Freeware and free partition magic for Windows 7, Windows 8, Windows Vista and Windows XP 32 bit & 64 bit. MiniTool Free Partition Manager Software Home Edition., with this you can create a bootable CD which you can use to set your start/boot partition.
I would try a couple of these options befor you send the system to the shop, if you do go to a shop get a fixed price for
repairing rather than just let them have a free hand