hello I have a problem with postgres

hello I have a problem I can not solve :(,, I have bad, because nothing of computers and need not work with a program,,

good when I try to start the pgamin III I get ""Error connecting to the server server closed the connection unexpectedly, esta probably Means, the server terminated abnormally before or while processing the request""

but sometimes I start with no problem,,

I have the postgrest 9.2, I hope you can help me ..sorry for my bad English...