Can email but cannot connect to internet via IE7

[t377y]

This is a very wierd problem which has appeared twice. I can receive email
POP/SMTP only when I remove the AC power supply to the LAPTOP. As soon as I
insert the power adapter my wireless connection is disabled. I cannot coonect
to Internet via IE7 either with or without power supply. Ehternet cable
connection performs the same. When I try to connect tot hte internet I get
the error message which flashes quickly in the status area
"Res://ieframe.dll/dnserror.htm# "

I have an ACER laptop Celeron 560 processor running at 2,13GHz running XP SP3

I sent the LAPTOP back under warranty when the problem appeared 3 months ago
but it was returned indicating nothing was wrong and it worked fine for a few
months but now the problem has returned.

I suspect the Power Supply may be faulty but it appears to be working fine
recharging the battery and the Laptop works ok except for email and internet
while the power supply is connected. Beside ACER sent the power supply back
so I assume it works fine?

Actions I have taken
1) checked all internet settings which are as they were before
2) ran virus checker albeit without the last 2 weeks updates because I can't
connect to get the updates. No virus or malware found.
3) downloaded IE7 install from another computer and reinstalled IE7 -
problems still here
Possible actions to try:
1) send query to MS newgroups but really scratching at straws?
2) reinstall windows XP?
3) find and install new drivers for network card(s)
4) install IE8 but I had problmes with this on my other computer and had to
reinstall IE7

Until I exhaust all possibilites I am relectant to return to Laptop to ACER
as I suspect they will send it back again and I cant really do with the down
time of 14 days.

Any advice / suggestions would be much appreciated

Terry

--
If it aint broke don''''t fix it