Resolved Intermittent problem in connecting to the Internet

I'm using a Netgear dg 834pn router connected by a LAN cable to my PC and wirelessly to two different laptops in the house. All three use different operating systems by the way - one XP, one Vista, one Windows 7.
At times none can connect to the internet .( and at times, all can) . When I say intermittent I mean it works fine for say two or three web-sites and then after a few minutes use - or maybe when trying to reach a site for the first time of internet usage in the day, I can't get a connection. ( Microsoft's "Diagnose problems" points to the router - but presumably can't pin-point any of the other possibilities ? )
I think it can't be problems within the machines, must be the router itself or the filter, wall socket or the ISP/exchange.
I have checked the router manual, and can't see anything worth checking or pinging.i.e. when I can connect, all the green lights are green where they should be, and when I can't they are off as is appropriate.
The only doubt here is that there is a test light which comes on when the router power supply is first made, which should light up then go out ; it does this , but it is an amber light not green. But the manual says nothing about colour in this specific case.
By the way, normally - before these problems started a day or two ago, the router is not turned off, even if I shut the PC down.

I have replaced the filter between wall socket and line to the router.

Is there any way of checking this router , or maybe I should just replace it ?
Or try a new wire between the filter and the router first ?

Any advice , please ?

 

Is the filter a splitter type with1 connection clearly marked ADSL (that goes to your router) and the other connection marked phone?

If not – remove it.

If you need a phone plugged in.
Use a common telephone line splitter at the wall outlet.
1 connection will have phone line directly to router.
Place filter on other splitter connection (to get rid of ADSL signal that’ll cause static) then phone.

 

The filter is a splitter type.

Update ; this morning, t he system worked properly for 4 hours ( of intermittent usage) then stopped. I now have the router located where I can see the lights on the bottom, and have printed the manual page so that I can see what is happening. When it failed an hour or two ago, I found that all the power, wireless, LAN connection etc lights were lit indicating all OK, but one light was out - which indicated "No PPP link, modem is off,or no ADSL connection ". I don't want to phone my Broadband provider - I get through to a call centre in India and it takes an hour to work through - often finding at the end of this that they don't know the answer anyway...
So I just switched the modem power supply off at the wall, waited a minute and switched on again - when all was well.
This seems to point to the router/modem as dropping out ? And the answer is a replacement ?

 

Wow – just did quick search.

Dropping connections seems to be a problem with that model.

Doesn’t seem like anyone came up with any definitive answers.
Saw everything from: using any Torrent software, Firmware upgrades (if needed), defective charger causing overheating, Windows XP.

Firmware upgrades never seemed to work.
Doubt overheating with time you’re running before a dropped connection.
Torrent seems like a possibility – if you’re using it.
Windows XP home – possibly - if being used as ‘server’. It has limited number of concurrent connections it can handle – believe it’s 5 (XP pro has 10).

A replacement seemed to work most often.
If under warranty seems like replacement time otherwise a different make/model.

 

I will assume that it is a faulty router, and try a new one.Thanks for the help I'll mark it resolved.

 

and further ideas...

It occurred to me, before I go and buy a new router, to look at the Manual, and then at the manufacturers site ; as a consequence I have done a firmware upgrade.
I'll wait and see what happens now - if the problem recurs or not , and revert to this after a day or so....

 

System has now remained good, with no drop-outs for almost 12 hours since doing the firmware upgrade.
Fingers crossed...