Unable to Access TP-LINK TL-WR543G Router & Change WiFi Password without Resetting

Hi,
I would like to change my WiFi password, but after entering the router's IP address into the browser, the page does not load.
I will add that the address that I enter in the url is written under the router.
I would not like to reset it, because the internet was set up by the guy who distributes this WiFi, and he configured the entire network for me, so I can not cope myself afterwards.
Oh, I receive the Internet with a router, and then WiFi is done via an access point connected to this router. (I have 2 computers at home, one of which receives the Internet via this WiFi.

Router: TP-LINK TL-WR543G
Access point: TP-LINK TL-WA500G
thanks.

I've tried, it doesn't work.

The point is that when I type in the IP address that is on the sticker under the router, this page does not even load.
Yes, I have the Internet, even when I disconnect the AP.
(The antenna from the router is on the wall of the house and it receives the WiFi signal from the transmitter.Then I have an AP connected to the router, thanks to which I have WiFi at home)

Set manually in the network connection properties the same address group as the router has. So if the router has 192.168.0.1 then set the computer to 192.168.0.5. The same applies to direct cable connection.

If connecting with a cable to any LAN port and computer and trying to log in to the router does not help, unfortunately it is probably a factory reset, or ask this guy if he did not block anything.

So change in the "properties of local networks" iP version 4 from automatic address assignment to the one I have at the IP address of the router?
If so, the default gateway has the same address as the IP address?

I did not change it, just checked the address through the ipconfig / all command and entered a different address, where instead of 1 it was 20 - Default gateway and two addresses were given and after entering the latter, a window for entering the username and password is displayed, and the model is given a router like mine, so it probably logs in well, Unfortunately, I do not know the password, the one I entered so far to connect via WiFi does not work. Maybe he'll give me that guy what he assumed, how he remembers, if not, I'll reset it.
Thanks for the answers.

Hello, have you tested the default login password? Check the logs: admin passord: admin, see also the router manual, it will be discussed there.
greetings

yes i checked admin and admin but nothing.
greetings

You typed user-admin password-s / n (serial number)

Probably the username or password has changed. Then only RESET will be able to help or the person installing the equipment. It was the same for me, but I was informed about it.

Unfortunately it does not work.
call him right away and we'll see what he says.

You have not a router, but an Ap, as the antenna is derived from it, which "takes" the signal
And even if I'm wrong, it will help you download look lan and look host
in the host, enter your address of this contraption, leave it in the background, A look lanem, make a scan.
After the scan, the gateway of this router will answer and give you the ip address. Enter this address, not the one from the bottom, into the browser, very often the method described by me allows you to determine the real access page, if you do not want to do a reset.
The problem is probably due to the fact that the admin in this Apek or the dhcp router has been set to on. This causes the dynamic allocation of the address and thus the access page changes

Nice eggs ...
I called the guy I got this net from.
And he told me that he would not give me this password because everything is set up as it should be, and that I do not have to change anything ...
However, I have two reasons to log in to this page:
1) Change the WiFI password
2) Assign the MAC and IP address of the phone (Samsung Monte) so that I can watch videos on it.

When I told him that he did not play videos and that he wanted to log in there, he said that it was to blame for the phone (apparently because yt normally works on others, and on Monte it does not work)
I found a video on the net how to make the monte videos work: http://www.youtube.com/watch?v=7Y5FYc8M8ws

How do I explain to him that I have to do this and that it is not the phone's fault? ...

Added after 21 [minutes]:

faraway.pl wrote:

You have not a router, but an Ap, as the antenna is derived from it, which "takes" the signal
And even if I'm wrong, it will help you download look lan and look host
in the host, enter your address of this contraption, leave it in the background, A look lanem, make a scan.
After the scan, the gateway of this router will answer and give you the ip address. Enter this address, not the one from the bottom, into the browser, very often the method described by me allows you to determine the real access page, if you do not want to do a reset.
The problem is probably due to the fact that the admin in this Apek or the dhcp router has been set to on. This causes the dynamic allocation of the address and thus the access page changes

thanks for the info. but now the problem is that the "internet ... provider" won't give me the password for that router.

It depends, buddy, whose equipment is .. if yours, even if only in the lease, the supplier is absolutely obliged to provide you with all the necessary data. Well, unless the contract says otherwise.
I advise you to read the contract carefully.
If the equipment is a supplier, unfortunately you only need to politely ask ..., explaining exactly why you need access to this data.

I paid for the Router and AP, this is also mine.

And you read the contract ?
Unless otherwise stated, you can gently request access data, of course justifying what you need them for (the equipment is yours and you have the full right to freely manage it). restrict the free use of your equipment in any way.
You can print this post and show it to the operator ,,, he will probably eat it out of spite, but the access data for your equipment just MUST give you.

Added after 2 [minutes]:

Or try the method I gave earlier to determine the "floating" access page due to dhcp.

Added after 7 [minutes]:

Hmmmm, finding the site will probably not do anything anyway, because he probably entered his password, and this can only be determined by rs, but this is a complicated method and you must have an rs cable

Thanks for the answer.
I read the contract, there is probably nothing written about it. You know what language it is written in ...
I don't care too much about it, but since I'm paying, I should probably be able to configure the hardware. When I buy a TV, I can change the colors in it, e.g.

Added after 1 [minutes]:

As for this program - I don't want to install, maybe some old ver. I have Win 7 64bit.

There is an even worse problem with 64 bit wines
Few applications work as they should, you can try the compatibility mode as those win 32 / x86 applications do not work.
And press the operator, because it is a scandal to block your equipment with its passwords
Greetings.

Exactly.
Thanks for the answers.

I'm finishing tamat.