In Windows 98, screen freezes during loading Win 98 screen. Error is ... An Internal Stack Overflow has caused this session to be halted. Change the STACKS setting in your Config.sys file and try again. Can NOT boot up in SAFE mode; cannot format hard disk. Have tried changing Stacks in Config.sys ... will not boot. Have tried deleting win.ini and system.ini and still get same error message. Any ideas? Thanks.

I don't see where your system.ini or win.ini files should be a problem. When a device in your system generates an interupt request (IRQ) the CPU stops what it's doing and saves all the data it was working on into a stack. Several interupts can occur at the same time and the CPU can handle them buy doing the same thing of saving data to stacks. However, if too many interupts are generated too quickly, you run out of stacks to dump to. That causes the internal stack overflow error. The only solution I know of is to increase the number of stacks or the size of each stack in the config.sys file. Try increasing the size of the stacks first. If that doesn't work, lower the size back down and increase the number of stacks. If that still doesn't work, increase both number and size. the first number you see after the stack= line is the number, the second is the size.

Thanks, but I've tried altering the STACKS command in the config.sys file ... which I don't think I should need because I'm running Win 98. But, I've tried STACKS=64,512 and 0,0 and 12,256 and 9,256 and 12,128 ... all without any success. Cannot boot to Win 98.

If you pull all the hardware out except the video card and default the Bios and it still happens,I think you've got a motherboard problem. Troubleshooting stack overflows