It seems like a compatibility problem. Waiting for answer..

go to Wireless/Wireless Settimgs/Channel Width/by default is in AUTO change it to 20Mhz, if that one does not solve your issue then the one on top Mode by default its 11bgn mixed change it to 11bg Mixed

mmm, my problem is about the repeater, this procedure does not work to me, there is something to this issue with repeater Uniersal

mmm, my problem is about the repeater

sorry i dont understand this one, answer to thread is about your TL-WA901ND repeater no other,

Curious, this where 2 changes in settings did you save and reboot twice if yes go to next step, the big issue with a repeater is to connect Smartphones and tablets, you have done that, so laptops its the easy part,
If you have Firewalls on Laps disable them.
Do settings adviced before in your ISP router too, if with all that still your laps dont connect, then changes have to be done to laps wireless adapters.
I had a friends case like yours, it did connect to ISP router but not through repeater.
There are 2 easy test to rule out security type, first connect Repeater via ethernet cable to your Lap, disable wireless adapter in Lap, check internet via wire.
second test, wireless connection, configure your 901 as AP with WPA/PSK2 security, use dif. SSID from your network, connect AP to router via ethernet cable using any of the output ports, yellow ones, and try wireless connection to AP, no go, change security on AP to WEP, if your laps connect, you have the answer.

i resolve the issue, actually the repeter work very well, i no made any change in the repeter, this issue is a problem with windows 7 and 8, actually i use wep security and windows 7 by default dont permit use wep security (in automatic form) only in the laptop or device with windows 7 create manually a connection wep.
1.- open centro de redes y recursos compartidos
2.- configurar una nueva conexion de red
3.- conectarse manualmente a una red inalambrica
4.- in network name put the ssid the repeter
5.- select "wep"
6.- put the shared key

i hope this information are util for you.

i hope this information are util (useful) for you.

Thank you, but is not, never have used WEP.
Known issue, that's why most don't use WEP security, slow throughput of data (la red es mas lenta) incompatibility and the easiness of someone hacking your network (te piratean el ineternet con mucha facilidad)
http://superuser.com/questions/523959/windows-8-wep-with-shared-key
Remember this is not a guessing game, the information needed, is absent from your thread.
As you post

actually the repeter work very well

Good Luck