It depends on what you mean by almost everything.
It will run 98% of all mame just fine. For some, that 2% is the deal breaker. Ridge Racer, Gauntlet Legends, and other games this might still struggle with.
Hyperspin it should run fine, and the vast majority of games it will run fine as well. For the price, its not a bad deal at all for a mame machine.
The biggest and most apparent bone of contention with this setup will be the lack of native Legacy Serial and parallell ports.
Truly, i wish that someone could tell me without a doubt what the latest and greatest legacy / usb 2.0 hardware is that will still run on windows ME Or 2000.
The only reason in this world that i upgraded to xp was because that the newest system i speced would not run under ME or 2000.
The funniest thing of all is This.
I was terribly out of date when i was forced to adopt windows 98 SE. I was also out of date when i was forced to adopt windows Me.
The funniest thing is that except for usb 2.0 the most recent changes and updates would always install under windows 95, Or 98 Se, even Windows 2000, Etc no matter what system you had.
It was in fact the same time Frame that Windows Xp was released and Product Activation Was Introduced, That it became painfully apparent even through simple upgrades that you couldnt just simply maintain your old ME or 2000 System and continue to resist Xp.