Steam stuck at Updating Steam Platform

[Purdy]

Has been like this for 3 hours, stuck at 89%.
I have closed it and restarted several times.
It has only recently started updating frequently after entering the screenshot steam beta, but today i just cannot get on steam, anyone else got the same problem or any ideas?

Sorry if its the wrong forum section.

 

[Purdy]

Go into the steam folder and delete the "client registry blob" file. Then restart Steam that normally cures most start up issues.

Thank you very much =>