Steam crashes and won't start up again - Steam support not responding

I've contacted Steam support about this but it's been nearly two weeks and they haven't responded.

Can anyone here help? Here is a condensed version of my ticket.

Quote:

Ticket number 2223-WRXV-5095 Recently I've started having problems with Steam. It will randomly crash during a gaming session, and then any attempts to start it up again will not work. Sometimes it doesn't even need to crash, it just won't go at all. It will show the verifyig window for a few seconds, if at all, and then vanish. If I try to start a game up from the desktop, it will do the same thing. So far, I've tried: Restarting (obviously) Running in aeroplane mode Searching for steam.exe in task manager (steam bootstrapper seems to come up for a few seconds before it closes) Antivirus scan Deleting a variety of recommended files in the installation folder, eventually the entire thing apart from the launcher Reinstalling (worked for about five hours of game time) Running as administrator (worked once, but later in another session it crashed and the same problem remains) Full uninstall (including removing Steam from the registry) (again, worked for a few hours) Downloading all pending windows updates and reinstalling the graphics card driver It seems Steam will run in safe mode. My specs: Lenovo Ideapad Z510 Windows 8.1 Core i5 4GB RAM Nvidia GForce 740M

Steam crashes and won't start up again - Steam support not responding