If you still have version 3.0.3 somewhere, you can probably open it, and go to "File" => "open" and see which default folder is opened... You could also use your OS's search functionality (depends on your os tough).

Last option, you can try to open C:\Users\[your username]\AppData\Roaming\Electrum\config with a text editor (like gedit or notepad++) and look for gui_last_wallet and recently_open

However, and i cannot stretch the importance of this enough: do not underestimate the odds of you running a malware version if you were prompted to install a "patch" or an "upgrade". If you are running a malware version, your virusscanner probably won't pick it up, and if you open your wallet with the malware version even once, or even for 1 second, you'll lose your funds straight away.

close electrum immedately, don't touch it again untill you've read the updated version of this post (look back in <5 minutes)

updated version: if you had version 3.0.3, you were running a version that was vulnerable to a phising attack. Since you say you were prompted to download a newer version, you HAVE to make sure you didn't download a malware version... Please, remove the "upgraded" version and download a 100% clean version from https://electrum.org/#home, then check if ThomasV's signature matches BEFORE you install the new version...

If there was *ANY* chance you were running the malware version, I'd urge you to install a clean electrum version on a clean pc, recover your old wallet from the seed, generate a new wallet on the clean pc and empty out your old wallet into the new wallet ASAP... unless you're 100% sure you didn't run a malware version, in this case you can just recover your wallet from seed right away or look for the wallet file in: C:\Users\[your username]\AppData\Roaming\Electrum\wallets.
If you open and decrypt your wallet from the malware version of electrum, your funds will be gone in a heartbeat.

I agree with all other posters so far, but decided to make a checklist... Some of these points were already mentioned by previous posters!:

• Make sure you run an official version (check ThomasV's signature)
• Make sure you run the latest version
• Make sure to encrypt your wallet using a STRONG, UNIQUE password
• Write down the seed phrase, store it in a secure, OFFLINE way
• Never follow links shown by electrum or by any other source, if you need a new version, download it from the official website and check the signature
• A desktop wallet is used to store smaller amounts of funds... If you want more security, buy a hardware wallet, properly generate a paper wallet or do an airgapped setup
• Make sure your OS is squeeky clean... Don't install any financial tools (like wallet software) on a system running a cracked OS, or an OS on which you install unknown, or out of date software
• An OS (especially windows) NEEDS a virusscanner, an upgrade/update plan and a properly setup firewall

Next to this, there are things that are not specific to electrum (like keeping your OS clean) that are also worth mentioning... Like a native segwit wallet means lower transaction fees, enabling rbf is a good idear (especially if you cheap out on fees regularly) and anybody who has access to the seed,  the wallet file + passphrase OR the xprv (or individual derived private keys) has access to your funds,...

BTW, to be honest, i don't quite like the title of this topic... Electrum is still one of the more secure desktop wallets around. Sure, it has had it's share of vulnerability's (like most other wallets), but i would still recommand it to new users that are looking for an SPV HD wallet...

Not exactly an api... But this post might help: https://bitcointalk.org/index.php?topic=5064946.msg47841891#msg47841891

99 - mocacinno

Thanks

I've helped dozens of people with similar problems in the past, some offer bounties some don't... It's very rare to see a man/woman of his/her word, usually the people offering bounties dissapear after their problem has been fixed... No biggie, at least after they pull something like that, the community knows they're not trustworthy, so it's better i lose a couple minutes of my time than the person asking for help actually does the same thing to somebody that invested more than just time.

In the OP's case, i'll just wait and see... He hasn't been online since yesterday...

@everybody: the OP's problem got solved because i actually took the time to use freely available tools and methods... You should always pay attention to the fee you pay, if you don't want to wait => don't cheap out on the fee.
IF, by accident, you underpay (for example, a huge rise in average fee happens a couple minutes after you broadcasted your tx), you can either search the forum for the free tools i used or for methods of speeding up confirmation time (rbf, cpfp), or you can ask for help...
However, if you offer a bounty and run away afterwards, i'll probably be tagging your account... If you don't want to offer a bounty, just ask for help without offering something, and people like me will still help you out (for free)...

In the meantime the tx has been confirmed by one of the pools i subitted it to...

I've pushed it to antpool, i'll also submit it to viabtc if i manage to add it at the top of the hour...

https://i.imgur.com/dJ20BJu.png

An other option is to do a CPFP, since you've only funding one address with the unspent output, is it fair to assume it's a self transfer? If so, you should be able to execute a CPFP to speed up the average confirmation time


EDIT: submitted to viabtc:
https://i.imgur.com/Gv6mo5u.png

I've also rebroadcasted the tx (eventough that wasn't necessary), now it's just waiting untill one of these pools solves a block, and hoping they gave your tx sufficient priority to get it in the top of their mempool...

Well, i'm a bitcoin enthousiast, but Libra has one thing bitcoin hasn't: a huuuuuuge marketing budget.
Eventough i haven't read the whitepaper of Libra, nor did i try to find sourcecode for a reference client, i'd still be suprised if the technology used for Libra would be much safer than the one used for bitcoin, however, the fact that it's such a big company that coupled it's coin to existing fiat coupled with an enormous marketing budget and endorsement of company's like VISA will give it an edge bitcoin has never had.

The thing is: Libra is not bitcoin... AFAIK, it's a centralised token coupled to FIAT markets produced by one of the biggest privacy-invading companies on the globe. The only thing that couples bitcoin to libra is the fact they both use blockchain technology.

Is your disk encrypted? If not, you can always access your data by booting from a usb drive or a secondary disk and mounting the disk with the os for which you forgot your password.

Wether or not you can reset your password depends on the os and your technical skillset

It has been a long time since i last ran vmware player (at work, we have power partitions, at home i switched to openVZ for my virtualisation needs a long time ago), but after some quick googling around, you should be able to go to "VM > Settings, click the Options tab, and select Guest Isolation", then disable "drag and drop" and "copy and paste". To disable the network, you should probably go to your network adapters on your local machine and disable the "VMware Virtual Ethernet Adapter". For the local folders: IIRC, the default options would be not to share any local folders, so if you use the default settings the folder sharing should be disabled already.

These are the  things that immediately come to mind... Maybe somebody else will weigh in on this topic and give some more tips and tricks?

Good luck!

In the past, there were vulnerability's in virtualbox that could have been exploited, but the odds of running a virus in a very recent virtualbox vm that's built to exploit any unpatched vulnerability's is very low. You do have to make sure you isolate the VM properly... If your network isn't disabled, a virus could spread over the network, same with shared drives and maybe those drag and drop options...

That being said, malware *could* exhause the host's resources, so it's possible your PC will freeze because of a virus running in a VM container, but this should be harmless...

Running in a VM is better than running in sandboxy afaik... the level of isolation would be a lot better in a virtual environment vs a sandbox on your system.

I wanted to add a sidenode to your pruning setting: you do have to realise that when you run a pruned node, a reindex will force you to re-download the complete blockchain again.... So, eventough running a pruned node is fine, it does limit some of the functionality.

You can always install vmware player on your local machine, just make sure the network is disabled, nothing is shared, drag and drop is disabled,...

source: http://Https://utwentebs.eu.qualtrics.com/jfe/form/SV_bDCu7uXoh38A8l

I've tested the code, and it seems to work fine (didn't finish the purchase tough)... I'm actually tempted to buy one, eventough i already have a Ledger HW.1, a nano S, a trezor model T and a trezor one (just because i like to spread the risk by using different HW wallets instead of keeping all my funds one one device).

My main problem is that the device will be sent from the US, and the 60% promo code + S&H still comes down to ~$54, so if the customs stop the package it will be taxed quite heavily... The import duty for a $54 package is ~€22,88, bringing the total to ~€75...

Still a very nice code tough ....

Well... I've noticed the ebay market being full of ripoffs... These sellers try to sell those old block erruptors to unknowing "victims" giving them false hope of free money.
In the future, their price might rise due to the collector's value tough... But that's about all they can be used for: a conversation piece or a piece of bitcoin history, but not for actual mining (well, in theory, they *can* be used to mine, in the same way as you can use your cpu or gpu... Burn a lot of electricity and get nothing in return)...

It's kind of hard to follow what you're saying, but if you try to send funds to an address managed by the same wallet, you'll only see the fee being deducted from your balance.

A transaction is being generated and broadcasted, the transaction has a fee, but since you're spending unspent outputs funding an address in same wallet , the only balance difference is the fee being payed.

Like i said: ethos gives you an image... You can write it to an SSD, HDD, USB, SAN, floppy (not really :p, a floppy wouldn't have enough space to hold the image).
But in case you don't want to use ethos, you can still try to answer some of my initial questions and we can see what went wrong on your first trial

You were talking about running the OS from your SSD, not an USB... And even then, you can always put the image on a new usbstick anyways, it's not like the stick will store your actual wallet, so if it is fried, nothing is lost but one or two hours of your time (offcourse, you shouldn't put important data on the same stick you run your mining os from)...