No internet connection on desktop PC

[#1]

HELP !!! I am at my wits end and at my age that's a long way

I have 2 laptops and one desktop PC in same room.
Laptops connect to internet first time every time via my netgear wireless router
Desktop running windows XP has only occasionally connected and most recently not at all.
Even though it shows 'connected to network' and signal strength 'very good' , IE6 (or IE7 I've tried both) says 'server not found' or 'no internet connection is available'.

Is it significant that when I check status there is a number for 'packets sent', but 'packets received' is 0 (zero)
All options in IE6 'connections' are as they should be I think
ie no boxes are ticked.
I can occasionally get connected by removing the netgear USB wireless adaptor and replacing it. Does this suggest a faulty adaptor, or a USB problem (I've tried every USB port I've got and no other USB devices have problems. But 'connected to network' and 'signal strength very good' messages suggest hardware is OK ?

If no one can help then next stop 'Samaritans'
Thanks

[#2]

Can you ping the router's IP address?

[#3]

If you right click your wireless icon in the task tray and select 'Status', what does it say in the 'Support' tab?

[#4]

Have you tried ipconfig /all from a command prompt, to see if you are actually getting assigned an IP ( i assume you are using DHCP). If this shows an IP address beginnig with 169, then you are not being assigned an address. Do you know how to set a static IP??. If you have got an IP beginning with 192.168.x.x, , are you absolutely sure your wireless security settings in the PC are correct. Some routers seem to be able to connect if its wrong, but wont let you do much else.  If you can ping the router as xenstar suggested, it would appear that your local LAN is working.  Can you try this system with an ethernet cable to rule out a windows issue??  If it works first time with a cable, then this would point to the wireless adapter. you could then try uninstalling the adapter drivers and software, and reinstalling them.
Hope this helps

[#5]

Not got Zonalarm by any chance? If you have a recant update has stopped internet access for a lot of people see other threads.
Have you got any encryption set on the router as this is the most likely cause of the problem turn it off reboot the router and see if it connects then if i does then theres the problem

[#6]

Quote from: Xenstar

Can you ping the router's IP address?

I don't really know what you mean

[#7]

Quote from: penfold

Have you tried ipconfig /all from a command prompt, to see if you are actually getting assigned an IP ( i assume you are using DHCP). If this shows an IP address beginnig with 169, then you are not being assigned an address. Do you know how to set a static IP??. If you have got an IP beginning with 192.168.x.x, , are you absolutely sure your wireless security settings in the PC are correct. Some routers seem to be able to connect if its wrong, but wont let you do much else.  If you can ping the router as xenstar suggested, it would appear that your local LAN is working.  Can you try this system with an ethernet cable to rule out a windows issue??  If it works first time with a cable, then this would point to the wireless adapter. you could then try uninstalling the adapter drivers and software, and reinstalling them. Hope this helps

IP address was entered manually because it coudn't acquire it automatically, and it is correct

[#8]

I can't check anything at the moment. The b****dy hard drive has failed now!!
I'm thinking of going back to pen and paper and good old fashioned shopping on a Saturday afternoon !
It never rains but it pours !