When you restart the computer you will automaticly go to trying to start Windows normaly and to go to safe mode you actualy have to hit the key to do so. So the default option is to try to start Windows and any other mode you will have to make a selection.
Thanks Stealthinator and inzone for your kind assistance!
The problem is now fixed. It was all down to foolishly installing Bitdefender, which caused my computer to crash and which, by remote assistance, took them 5 hours to fix in total, 2.5 hours of which was to get their own programme removed.
During boot up the options would appear, but when normal mode was selected a blue screen appeared which would then revert to the options appearing again and so on