Access denied message using Linksys Adapter

I have a Linksys bases wireless network at home on which I have five active
PCs. No current problems on the existing setup.
I have brought out a desktop from retirement after 18 months (Dell Pentium
4, 1.6 Mhz, 256 Mb RAM) which needs XP updating - Service Pack 2, security
updates etc. I attached a Linksys 2.4 Ghz, 802.11b, Wireless USB Network
Adapter. I found the driver OK and access to the network was confirmed. I
have a 4 Mb cable access.
When I open up Internet Explorer and attempt to access individual sites,
some - apparently at random (though the same ones) are OK and others
(including Windows Update!) are denied with a page giving the following
message: "FORBIDDEN You were denied access because: Access denied by access
control list"
All other PCs on the network have full access to all sites.
If I use the onboard modem on the pc to access those same sites, I get
through without problems, though very slow of course.
Can XP be putting an extra control on my new network access? I have tried
putting the XP both on and off. I have not enabled any controls.

Can anyone shed light on this for me, please?

Many thanks in advance

Geoffrey

"FalcoPilot" wrote:

> I have a Linksys bases wireless network at home on which I have five active
> PCs. No current problems on the existing setup.
> I have brought out a desktop from retirement after 18 months (Dell Pentium
> 4, 1.6 Mhz, 256 Mb RAM) which needs XP updating - Service Pack 2, security
> updates etc. I attached a Linksys 2.4 Ghz, 802.11b, Wireless USB Network
> Adapter. I found the driver OK and access to the network was confirmed. I
> have a 4 Mb cable access.
> When I open up Internet Explorer and attempt to access individual sites,
> some - apparently at random (though the same ones) are OK and others
> (including Windows Update!) are denied with a page giving the following
> message: "FORBIDDEN You were denied access because: Access denied by access
> control list"
> All other PCs on the network have full access to all sites.
> If I use the onboard modem on the pc to access those same sites, I get
> through without problems, though very slow of course.
> Can XP be putting an extra control on my new network access? I have tried
> putting the XP both on and off. I have not enabled any controls.
>
> Can anyone shed light on this for me, please?
>
> Many thanks in advance
>
> Geoffrey

PS. I mean, of course, putting the XP Firewall on and off. Sorry for the
confusion.

Still no joy today with MS sites. But, for instance, while looking for a new
ISP for a friend, I find that I can access any number of these websites
without a problem. Very weird!