Hi I've accidentally deleted my start menu on windows 8.1.  How do I restore it.

Thank you

How did you deleted it?

It is part of Windows and there is no interface to delete it.

Did you modify your registry or did you used any software?

May be you hide, to test this move your mouse down and see if it appears.

Hi,

Could you access "Update and recovery" UI from PC settings?

If no, another way is to press the Power button at the Windows login screen. Then, press and hold the SHIFTkey on your keyboard and click Restartto boot into recovery console.

There you could choose restore your PC to an earlier point in time as this guide:

How to  refresh, reset, or restore your PC

http://windows.microsoft.com/en-IN/windows-8/restore-refresh-reset-pc