|See page 72 of this PDF:|
"Anything after IE6 will slow it down too much as well as most antivirus programs"
He has a 2.4GHz P4, not a P166...lol. IE8 would easily run on that machine; I've even seen P4 systems run Chrome and IE9 on Win7 without difficulty. It all depends on the amount of RAM installed. 1GB would easily be enough for an XP system.
Socket 939 | Dual-core Opteron 185 @ 3.2GHz | 4GB | 1.0TB | Win7 x64
GeForce GTX 460 1GB | X-Fi Ti Pro | A8N32-SLI Deluxe | Antec P182