My Minecraft isn't opening?

It was working 10 minuets ago but it has just stopped now. I'm on a sony vaio laptop, I've uninstalled and reinstalled java and I've redownloaded minecraft but its not working. When I restart my computer Skype is also having issues so they might be connected. I click on the icon for minecraft and it just doesn't load. In task manager the process turns up in the process bar and then it just disappears… Help please!

I CAN't GO IN MY HOUSE IN MINECRAFT?

I was just playing minecraft and I can't go into my house near the door there's like an invisible indestructible wall that can't be breaker even in creative. Does anyone know why?

Can I run Minecraft smoothly with my specs?

These are my specs to my laptop. It's a gateway Model M-2625U, 2gb RAM, 160HD, AMD turion x2 64bit, ATI RAdeon premium graphics Vista home premium. I took out 2gb of ram, is that the reason it does run Minecraft smoothly? Should I upgrade my ram back to 4gb?

I can't get into minecraft?

So I bought mincraft for my computer a while ago and I was not able to go online (and I'm still not able) so I quit after a while and then I came back and there was an update so I tried to update and it won't let me and into my mincraft game and go online with minecraft!