I press F8 this is OK. But it states that it will start in normal mode in 25 seconds unless I press one of three varieties of safe mode options. My up & down arrows fail to operate at this stage & I am stuck until it goes into normal mode and eventually Windows Troublemakers Agent (WTA)appears for the 100th time. To get rid of WTA I need to be in safe mode. I have changed the keyboard from USB to PSB vice versa etc to no avail. Please help - how do I get into safe mode automatically?

One solution is to boot windows up normally, with no safemode.
From the start menu go to Run--msconfig
When in system config click the Boot tab and you'll see a menu at the bottom left.
Click the Safe boot checkbox and Network and then Apply and Ok. Next time you reboot it should auto boot into safemode with networking with no extra input required.

Oh just to clarify, you don't need to check Network in the menu, that's only if you want internet access while in safe mode.