Hey thanks for the tip about "blockchain.info" that worked.
My wallet imported it turns out its was my empty wallet from Bitcoin-qt.
In my haste I've saved the wrong wallet. My coins must have been in the Multi-bit wallet file.
The one I should have copied. Thats with the thief now but its passworded so they are probably lost forever.
The laptop may have already been formatted.

Out of curiosity is there a way to look up the block chain and see if the have been spent ?.

That was an expense way to learn about back ups.

What was the other poster saying about private keys ?. If I back copy a wallet file from any bitcoin client do I need anything
else to go with it for future reference ?

Thats really rude.

What the hell would make you think that ? I didn't steal anything from anybody.
My laptop was stolen in the Philippines along with my whole bag. It was not a pleasant experience.

I dont know much about bit coin at least you got that part right.

But what im telling you is true.

I have a file called wallet.dat which I created in a hurry four months ago from quickly googling a how to guide.

Are you telling me that I need a private key to go with the file or its useless ?

In hind sight I think I copied the wallet file from Bitcoin-qt and not the other wallet where
my coins were and its probably empty anyway.

My story is this.

I decided to dabble it bit coin and purchased 12 coins at MTgox a few months ago when they were a bit over $100 each.

I initially downloaded Bitcoin-qt to my macbook air then discovered a serious network connection was need to run
this wallet so I switch to Multibit (I think although it may have been some other light wallet).

After Mtgox sent me the coins I sent 10 coins to an online currency trading firm with the intention of dabbling in some small time currency trading and kept 2 in my wallet for a rainy day.

I quickly read a guide to backing up bit coins off google. I put a password on my wallet and then found a file
somewhere on my hard drive which I though was my wallet and copied it to a USB key.

A few months later when on holidays in a third world country my bag and laptop were stolen.

This has caused some major problems.

1) The trading company is claiming I can only withdraw my 10 coins to my old wallet address.
This must be one of their own rules because bit coins dont work like that as far as I know.
I should just be able to prove who I am and send them a new wallet address.

2) The file I backed up with the 2 coins in it is called wallet.dat. Googling reveals this is the wallet file for Bitcoin-qt not
Multibit. However I cant remember what happened when I backed it up.
    1) I may have renamed the file to wallet.dat
    2) I may not have been using Multibit are there any there any other light fast wallets out there ?

In any case if somebody technical knows a way I can check the wallet.dat file I have to find out where it came from.
If it still has coins in it and your help unlocks them I will tip for sure.

Thanks.

Mark.

Hi Everybody,

Im new to bitcoin. Ive read all about how it works but and I think im about 70% of the way to understanding it.
But there are still some burning questions that need answering.

Here are my questions ...

I understand bit coins are stings of numbers that can be printed out and stored on a physical sheet of paper.
Let say somebody did this and I grabbed the paper when they weren't looking and photo copied it.
Or just grabbed their laptop and copied their bitcoin wallet.

Now there are two copies of each coin in the world. What happens if we both make a purchase with those
coins. Is it a race to spend them first ?.

When I make a purchase with a bitcoin lets say my coin is 987654 and I buy a coffee mug
does the seller now receive that exact numbered coin 987654 and some kind of transaction is logged or
does the coins number transform when he receives it in his wallet into say 123987654 for example and coin number
987654 is now spent and ceases to exist. ?

People say there is no central bitcoin server so does that mean that every wallet on every computer must hold a record
of all transactions that have ever happened ?. When I tried to install the bitcoin wallet on my mac it took days and still didn't sync.
I gave up and installed a bitcoin lite wallet instead and that worked ok but what does this all mean ? Am I at some kind of disadvantage by using the the lite wallet ?

Thanks for any advice in advance.

Mark.