Hi Methyl i have tried pressing the shift key and also F8 at the same time ..it comes up saying it couldnt load windows and i could try to restore to an earlier time, when i press restore it just goes to a black screen with a buffering circle. Thats as far as it will go.
The one way to reboot into safe mode that works every time is to run mscongif.exe, and click on the boot tab of the pop-up window - at the bottom left are the boot options including the tick box for Safe Boot and you can set options for that (Network is a good one).
Note that you will need to run msconfig.exe again to turn off the safe mode boot.
Press 'Windows' and 'R' buttons both at the same time. A run box prompts. Write msconfig in the run box. 'System configuration' window opens. Click on 'Boot'. Check 'Safe boot' and finally click on 'OK'.