Story continues... I played with IRQ steering - total disaster :-( It seems that Win is not able to assign correct IRQ to USB2.0 without BIOS. I tried many combination, for the moment I had IRQ 3 assigned to USB2.0 (not working anyway), but it could be displaying error in Device Manager. I did not try IRQ steering = disabled with Plug and Play OS=No, but it looks like BIOS always gives IRQ 10 to both USB2.0 and SATA controller. Disabling ACPI BIOS IRQ table causes only loosing of both IDE & SATA controller. So to install USB2.0 correctly I need to live with IRQ steering enabled. That was bad part of the story. I started to look at options I have for different controllers. Nforce3 250 has one dual channel IDE controller ( I have one HD and one DVD on it) and one dual channel SATA controller. Win98SE installs drivers for both, however I don't need it for 98SE (SATA driver is NTFS used under XP). Removing device for SATA causes both device to be reported as not working correctly, but I found option on Dual IDE controller device to set 'No channels enabled' and then... NO IRQ for SATA ANYMORE !!!! Installed OrangeWare USB 2.0 drivers, IRQ 10 assigned and system works, USB flash detected. I managed to install almost all drivers and updates now, including IE6.0. Some still left including sp2.1a. In my case this is ok, however it would be more challenging to make SATA drive FAT32 formatted working under Win98SE. I don't think so, it is possible to install W2000 SATA driver under 98SE, but can have a look. Anyway, issue with USB2.0 and SATA seems to be solved for me, I will let you know after installation is completed and tested.