<p>Yes, mostly, but there are some things you should know.</p>

<p>Your wallet is stored as a separate file. Your wallet file gets changes written to it <a href="https://bitcoin.stackexchange.com/a/854/516">as new blocks are received and transactions are made</a>, etc. The chances of a crash occurring during a write to your wallet are probably minimal, but <strong>you should have a <a href="https://en.bitcoin.it/wiki/Securing_your_wallet" rel="nofollow noreferrer">backup of your (encrypted) wallet</a> anyway. This is by far the most important point.</strong> Once your wallet is encrypted with a very strong password (the client provides this function), you can store copies of it in insecure locations, so you always have a copy somewhere - store it in gmail, send it to your family etc. You should only need to make an additional backup every 50 transactions. Bear in mind the receiving address descriptions aren't encrypted though. Running the client with the -rescan option may fix minor issues.</p>

<p>The client will refuse to work if a failed attempt at double-spending is detected, but that's not really what you're asking. Besides, <a href="https://bitcoin.stackexchange.com/q/3654/516">there appears to be a fix for the problem</a>.</p>

<p>The block chain takes a long time to download, so there is a risk that a crash would required you to download it again. If the client is closed (gracefully) while it is downloading the block chain, it resumes where it left off with no issues; I would guess it would probably do the same thing in the event of a crash, but it's only your copy of the block chain that's really at stake. </p>

<p>Realistically, once you've got your wallet encrypted with a strong password and backed up in multiple locations, the biggest remaining risk is from theft through a virus or malware. <a href="http://gavinthink.blogspot.co.nz/2011/06/why-arent-bitcoin-wallets-encrypted.html" rel="nofollow noreferrer">Quote from Gavin Andresen</a>: "If your computer is infected, then it cannot be trusted, and there is no software in the world that can keep your bitcoins safe if they are stored on it."</p>

CC BY-SA 3.0
2012-06-19T08:17:40.967Z
"I would expect your wallet file only gets changes written to it when you send bitcoins or create a new address".  The wallet also includes your address book and transactions affecting your balance.  So receiving funds or labelling addresses causes a wallet write too.
Chris Moore
CC BY-SA 3.0
2012-06-19T08:54:49.453Z
Have you got a reference for that? It would seem unnecessary to alter the wallet when funds are received; that information is already stored in the block chain.
Highly Irregular
CC BY-SA 3.0
2012-06-19T11:38:55.550Z
@HighlyIrregular Hmm, I'm not afraid of my computer being affected (that's a different issue), but more of whether the client itself is built to be crash-resistant (like Chrome) or crash-means-good-luck (like MS Word).
Pacerier
CC BY-SA 3.0
2012-06-19T19:01:10.497Z
@HighlyIrregular Did you ever hear of the -rescan option to bitcoin-qt?  It's used when the wallet is missing some transactions that are in the blockchain, and causes bitcoin-qt to rescan the blockchain, copying relevant transactions into the wallet.  http://bitcoin.stackexchange.com/questions/853/what-do-the-different-dat-files-contain/854#854 is written by one of the client developers, if you need a reference.
Chris Moore
CC BY-SA 3.0
2012-06-20T08:18:55.570Z
@ChrisMoore, thanks! I learnt something today! I've updated my answer too.
Highly Irregular
CC BY-SA 3.0
2012-06-19T07:13:42.093Z
2012-06-20T08:18:06.290Z
2017-04-13T12:47:32.940Z
Highly Irregular
<p>I'm running the "official client" (<a href="http://bitcoin.org/" rel="nofollow noreferrer">12 MB zipped version</a>) on a Windows platform.</p>

<p>What are the risks (to my wallet) when the computer crashes due to overheating, BSOD, power failure, etc?</p>

<p><img src="https://i.sstatic.net/PVS1U.jpg" alt="enter image description here"></p>

<p>Is the "official client" crash-resistant?</p>

<bitcoin-core>
Is the "official client" crash-resistant?
Pacerier
# Is the "official client" crash-resistant?

(Asked by: username_0 on 2012-06-19)

I'm running the "official client" ([12 MB zipped version](http://bitcoin.org/)) on a Windows platform.

What are the risks (to my wallet) when the computer crashes due to overheating, BSOD, power failure, etc?

![enter image description here](https://i.sstatic.net/PVS1U.jpg)

Is the "official client" crash-resistant?

**Tags:** bitcoin-core


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## 1 answers

### Answer by username_1 on 2012-06-19. Score: 4 | Accepted answer

Yes, mostly, but there are some things you should know.

Your wallet is stored as a separate file. Your wallet file gets changes written to it [as new blocks are received and transactions are made](https://bitcoin.stackexchange.com/a/854/516), etc. The chances of a crash occurring during a write to your wallet are probably minimal, but **you should have a [backup of your (encrypted) wallet](https://en.bitcoin.it/wiki/Securing_your_wallet) anyway. This is by far the most important point.** Once your wallet is encrypted with a very strong password (the client provides this function), you can store copies of it in insecure locations, so you always have a copy somewhere - store it in gmail, send it to your family etc. You should only need to make an additional backup every 50 transactions. Bear in mind the receiving address descriptions aren't encrypted though. Running the client with the -rescan option may fix minor issues.

The client will refuse to work if a failed attempt at double-spending is detected, but that's not really what you're asking. Besides, [there appears to be a fix for the problem](https://bitcoin.stackexchange.com/q/3654/516).

The block chain takes a long time to download, so there is a risk that a crash would required you to download it again. If the client is closed (gracefully) while it is downloading the block chain, it resumes where it left off with no issues; I would guess it would probably do the same thing in the event of a crash, but it's only your copy of the block chain that's really at stake.

Realistically, once you've got your wallet encrypted with a strong password and backed up in multiple locations, the biggest remaining risk is from theft through a virus or malware. [Quote from Gavin Andresen](http://gavinthink.blogspot.co.nz/2011/06/why-arent-bitcoin-wallets-encrypted.html): "If your computer is infected, then it cannot be trusted, and there is no software in the world that can keep your bitcoins safe if they are stored on it."

> **Comments:**
> **username_2**: "I would expect your wallet file only gets changes written to it when you send bitcoins or create a new address".  The wallet also includes your address book and transactions affecting your balance.  So receiving funds or labelling addresses causes a wallet write too.  
> **username_1**: Have you got a reference for that? It would seem unnecessary to alter the wallet when funds are received; that information is already stored in the block chain.  
> **username_0**: @HighlyIrregular Hmm, I'm not afraid of my computer being affected (that's a different issue), but more of whether the client itself is built to be crash-resistant (like Chrome) or crash-means-good-luck (like MS Word).  
> **username_2**: @HighlyIrregular Did you ever hear of the -rescan option to bitcoin-qt?  It's used when the wallet is missing some transactions that are in the blockchain, and causes bitcoin-qt to rescan the blockchain, copying relevant transactions into the wallet.  http://bitcoin.stackexchange.com/questions/853/what-do-the-different-dat-files-contain/854#854 is written by one of the client developers, if you need a reference.  
> **username_1**: @ChrisMoore, thanks! I learnt something today! I've updated my answer too.  

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