automatic archivers will also pickup the trojan/rootkit so no go there.
check out ebuyer.com for laptops, the prices arn't too bad.
i blew a grand a few months ago on a Samsung NC10 (10" netbook) and Toshiba SatPro L300 (15"laptop)
(along with maxing the Ram out and chucking in 500GB Hdd's)
if you after playing games then you will need to spend ovr £700 for the laptop to get the higher spec graphics chipset.
I got a couple of Toshiba Satilite A30's for sale @£160 each
(P4 (2.8/3.0Ghz), 15"Tft, 1GB ram, 40GB Hdd, WiFi, XP-Pro) with original software packs, laptops in good condition, hardley used.
PM me if interested
as ever the prices are coming down, with new kit coming out all the time...