Random yellow flag on network connectivity

Wow, it looks the computer are taking advantages over me...
this time is my mom's computer

it's an old IBM Thinkpad t42 running Windows 7

as always, everything was fine, but from a month ago im paying attention to a random problem with the network on that laptop, sometimes it gets internet acces, sometime not, i switch ports (i have a small router) with no results, i connect it directly to the modem and no result, i run the "problem solver" (sorry if i misstranslate, the system is in spanish so i guess that is the name in english) for networks.. and sometimes works, i tryed to sing in with live messenger with no succes and i run it's troubleshoter, and the test results list stops in "default gateway", i hit "repair" and sometimes works, now since yesterday nothing work,s the system has no access to internet, i have read that the problem could be the driver, im not sure about that since there has not been any change on drivers and it did work before....

please help!

if there is something wrong with the router, why the problem persist wven wen i try with another network and connecting directly to the modem?

i dont know much about networks, but i can not imagine that a configuration problem can pass form one OS to another in the same computer, i have linux puppy installed on that computer in case windows fail, i tried accessing to internet through puppy with no success, so i got to a point where i think the network card is bad o, but suddenly the the "fix a problem" of network wizzard did solve the problem, and now im online again (in windows)...

whats going on?

Anthony said:

Could be a driver problem, windows might have updated the driver when you installed windows updates.

Try Installing another driver to see if that helps. Check your Ethernet cable too!!

mm. yehh.. i suspect about the driver too, what i dont understand is why happen the same in the other O/S...

Dwarf said:

Check the controller properties, as shown below, and ensure that the option Allow the computer to turn off this device to save power (Spanish: Permitir al equipo apagar este dispositivo para ahorrar energía) is unchecked, as shown below. Then reboot.

thanks for the translation!
and yes, that option was checked, i will use that computer for the whole day to see if the problem came up again.

Dwarf said:

kharl said:

thanks for the translation!
and yes, that option was checked, i will use that computer for the whole day to see if the problem came up again.

Checked? It should be unchecked.

Yeah, sorry i meant unchecked, and since that last message i have been using that computer solving the a video driver issue, downloading drivers files.. you know.... and no yellow flag.

so, i think i can check the thread as solve.