Abdussamad thank you very much for this, to add on your reply the ''remainings'':

2: As wallet id, I meant ''address''. For receiving case, you told me I need to share the address to which I want to receive bitcoins. But what if I want to receive the bitcoins funds to address I have never used before? For this I might need to create new address BUT you told me I cannot manually create address (neither one nor more) within electrum. However you said I always have 5 unused ones. This word ''always'' got my attention. Since you were saying so, I assume as soon as I receive ANY bitcoins amount to ANY address, NEW unused address (never been there yet in my electrum) will Automatically occur. Is this correct or not?

If correct then something needs to happen to either of other addresses - to either the address which got the bitcoin payment and caused (assuming what I previously asked is correct) new address to automatically occur (if to this one, what happens with received payment?) OR to any other one (e.g. the one that has zero balance). Something happens here to old and/or used address otherwise new address wouldn't occur?

5. Once again assuming my understanding about ''Automatically occur'' above is correct: Since I cannot delete addresses, this means as long as I will actively use electrum, the list of addresses will only raise larger and larger? Obviously I am referring to the RECEIVE tab and Not History tab. In the History tab, its logical the answer on this question is positive but not so logical for RECEIVE tab, thats why I typed this.

The rest whatever I was asking was solved. Thank you! Only wanted to still add what I just did in this message.

Thank you to both of you for your replies but I don't understand what are you saying. I asked 5 different questions and have no idea to which one where you referring to?

jbrnt I guess you were referring to first one out of 5, thats only a guess but what if I would like to move the file to new computer? Is ''default_wallet'' file located in the path I mentioned in my first post enough or do I have to copy to new computer anything more?

Questions are different from each other and one answer cannot be related to more than one question. Yes I have 12 words seed but this isn't anyhow related to any word of any question I asked. Privatekey was I think (could be wrong) imported from old bitcoin-qt software but neither this is anyhow related to what im asking. Being confused because you didn't mention to which question you are answering. Anyway, whenever you will be available and when/if you would be willing to, I would like to kindly ask you if you could please read my exact questions again, perhaps more carefully, so you can see what I am really asking. Thank you in advance and apologizing for another post but im new to Electrum and original FAQ doesn't help for getting info on my listed 5 questions.

Hi All,
I cannot find my needed information on offical electrum.org's FAQ page. Although I have several questions, I would appreciate a lot if anyone could be please so kind to answer them. I even tried to contact developers of Electrum bitcoin desktop application but I haven't received any reply at all. My questions are:

1. When switching to new computer, is it enough that I copy to new computer from old one only default_wallet file (regardless of difference in Windows OS versions) located in (god knows what extension it is, can be .dat):

C:\Documents and Settings\USERNAME\Application Data\Electrum\wallets

OR do I have to move something else (e.g. entire ''wallets'' folder, entire ''electrum'' folder or even entire installation folder located in Program Files and NOT Application Data) on new computer also to prevent losing my btc funds? Or is that only single file enough?

2. Often I would like to switch wallet id address for both receiving and sending case. Where and how can I do this? On tab SEND there is for sure not such possibility. Also on tab RECEIVE I also don't see anything like creating new receiving id and/or new sending id. Where and how can I create new address? I expect to be able to change for both receiving and sending the address unlimited times. If this isn't true, if this cannot be done (there is a limit), please let me know.

3. In RECEIVING tab, there says like ''Main Account'', ''Receiving'', ''Change'' (here is nothing what would help me getting answer on second question), ''Imported''. But there is no sending id address. Where can I see within Electrum desktop application from what id address am I sending the payment? Is ''Imported'' the same as ''Sending'' which I doubt?

4. Under ''Receiving'' in RECEIVE tab, I have four different ids. Therefore I assume I can choose whichever I want to provide to the payment sender who is going to send me the bitcoin funds. Lets further suppose I have received (and remained - I didn't use it) some bitcoin funds in more than 1 of those receiving ids. E.g. in all four. In the left bottom corner of Electrum says ''Balance:'' which is probably showing the balance in wallet. I think I know the answer on the following question but I would still like to ask to be sure Im correct: Is this balance in left bottom corner the sum of balances of all/any receiving id wallets or only single (or only particular) one(s)? I think it is balance as sum from ALL receiving wallets ids but im not sure. Please answer me on that.

Additionally: What happens if the quantity of bitcoins I want to send exceeds the amount available in particular receiving id wallet address? I probably cannot define the order of wallet receiving ids (from where to take funds for payment) anywhere. Are the rest of wallet ids (until amount matches the one I want to send plus fees [Electrum requires fees]) chosen as source of payment 100% randomely?

5. Is it possible and if yes, how, to delete receiving/sending wallet id if i don't want to use it again? I researched for this but there is no Delete option. Of course for deleting receiving wallet id, the major condition is that i do *NOT* lose the balance on wallet id. Im not sure if I can send from one (my own!) to another (my own also!) wallet id to be left with zero on receiving id and freely delete that particular id.

Thanks a million times in advance if someone could please help... I hope there is some way to do that, specially for second question but I cannot see that option to create new (unlimited quantity for unlimited time) wallet ids anywhere. Thanks again in advance!