The official MAME website offers a small selection of games and files for free, non-commercial use, which may include necessary BIOS files depending on the version.
“With the 0.201 build, MAME has changed how it implements QSound. The 0.201 full romset now lists both qsound.zip and qsound_hle.zip. These two files are identical internally... you can just copy qsound.zip and rename the copy as qsound_hle.zip.” LaunchBox Community Forums · 7 years ago
Move the downloaded qsound_hle.zip file directly into your default MAME ROMs folder. The standard path is usually: C:\MAME\roms\ 3. Match Your MAME Version
If you're getting a "missing files" error for games like Street Fighter Alpha or Marvel vs. Capcom
