I just installed this fantastic game on my new computer (recent-decent one)
and it lags, something it didn't do on my old-obsolete one.
Is it due to the fact that I went from windows xp 32bits to windows 10 64bits ???
(for some strange reason I couldn't find the computer thread, sorry
Schecter Hellraiser C-7
Ibanez VBT700
Ibanez SZ320
Yamaha Pacifica 112
Crafter D8/N
Peavey Transtube Bandit 112
Peavey Grind Bass 5 BXP NTB
Dunlop Dimebag Crybaby
get the hd version
it's all just coming back
it's all coming back

it's all coming back to me
On mine to play the original I have to Ctrl+Alt+Dlt to the task manager and end the explorer.exe process.
You tried running it in compatibility mode for XP and updating your drivers? It doesn't look good though. After a little googling it looks like that game has been having that exact problem for years.