Do you have UEFI or bios.
If UEFI the following is not about the sparky installer and not Sparky, but for basic background - https://jenkins.debian.net/userContent/installation-guide/installation-guide-amd64/en/ch03s06.html#bios-setup
(which is for the testing version of Debian) you can glance at section 3.6.3 for some basic background on uefi. This source is very up to date as it is a crucial part of the new upcoming stable.
and from Debian Wiki on UEFI (which is geared toward stable, while Sparky is based on Debian Testing)
Dual-booting systems currently installed using BIOS fallback boot
Quite a number of early UEFI systems were shipped with a non-UEFI installation of Windows 7 pre-installed, and the firmware set up to attempt UEFI boot first and BIOS boot second. This worked fine for users, but the moment a new operating system was installed alongside that copy of Windows, it would be difficult/impossible to dual-boot it.
debian-installer will now warn the user if it is booted in UEFI mode but can find it only non-UEFI existing OS installations. It gives them the option to switch the installer to non-UEFI mode from this point forwards so they don't break potential dual-boot setu
I am guessing you have read https://sparkylinux.org/wiki/doku.php/live_installer
Please review your bios or UEFI setting for you motherboard
Please give more info about when in the install it failed and how if failed.
Also how did you prepare the USB stick (if you used a USB stick).