Incompatibilities between Win 98 and many models' power management and other BIOS features have prompted laptop manufacturers to post advisories against upgrading to the OS before installing BIOS upgrade patches. As we went to press, manufacturers had reported conflicts in a number of models.

û Compaq offers a comprehensive list of Win 98 incompatibilities and work-arounds, organised by product (including desktop PCs) at www.compaq.com/athome/win98/downloads.html.

û Dell recommends waiting to upgrade newer Latitude models until it releases a performance-enhancing "system patch" (check www.dell.com/products/notebook/latitude/98upgrade.htm for more information). Older models may not get the patch.

û Gateway suggests upgrading Solo 9100 systems set up with earlier BIOSes to Version 8.41 (www.gateway.com/home/support/hardware/9103) to fix a CardBus problem under Win 98. Microsoft also reports that Win 98's resume mode doesn't work right with the video chipset used in some Solo 2300 models.

û IBM says it will be releasing a patch for ThinkPad models to improve ACPI support in Windows 98 (see www3.pc.ibm.com/techinfo/12e22.html).

û Sony offers thorough solutions to Win 98 upgrade problems with its portable and desktop computers, including links to driver updates, at www.ita.sel.sony.com/support/pc/win98_2.html.

û Toshiba recommends not upgrading many models before installing a forthcoming BIOS upgrade with better ACPI support (see www.csd.toshiba.com/tais/csd/support/techsupport.html).