One PC in home network much slower wireless speed

[fiesata]

I have 4 PC's on my home network have broadband up to 24 meg which delivers an average speed of 13-14 meg
Recently reloaded laptop as it ahd a few minor problems which are expected after running for nearly 3 years on XP
To cut a long story short I now only get 8 meg on wireless only just over 50% of the others - tried -- upgraded wirless driver -assigned IP address in router - disabled firewall- antivrus - checked for malware /apyware etc - tried USB wireless adaptor same speed - changed wireless channel - it was at the same speed as the others before the reload - it has a Broadcom wireless card connected to a DG834N Netgear router

Does anyone have any other ideas please - otherwise the laptop runs really well

Thanks in advance

[ChuckFickens]

How are you checking the speed? and are you sure nothing else was using the connection at the same time?

Also did you install the chipset drivers for the laptop? (not that I'd really expect them to make any difference to this, but cover all bases and all that)