You can use Ventoy to have multiple ISOs in a single USB drive. When creating a new USB, make sure to enable Secure boot from Options. If there is a problem booting in or there is a weird blue screen, read this or search for Ventoy Secure Boot in UEFI mode.
My current setup (on a 16 GB thumbdrive)
- Fedora 37 x64 Live ISO (2 GB)
- Hiren’s BootCD PE v1.0.2 (3 GB)
- MemTest86 v4.3.7 (1 KB)
- MemTest86 v10.3 (1 MB)
- Windows 10 22H2 x32 Spanish_Mexico (4 GB)
- Windows 10 22H2 x64 English_International (6 GB)
- Windows 11 22H2v1 x64 English_International (5.4 GB)
You can download Windows ISOs from Microsoft Software Download Listing.