If the system posts, and can load windows.
The solid beeping tone is saying that a fan has failed, either on the cpu cooler of your system, or any case fan
And is not spinning, or is spinning at to low of an rpm speed.
The sound can differ depending on what bios chip the board contains.
So the other constant sound can be related to a Pci-e graphics card if fitted to your system not being seated in the Pci-e card slot properly or board saying it cannot see the card.
It can also include that if the Pci-e graphics card requires power fed directly from the power supply that there is insufficient power to the card.
It can be due to that,or the 12v E-atx power connector on the motherboard also being loose or incorrectly fitted.
As I said it depends on what bios chip the motherboard has an uses, because they all give slightly different bios beep code errors depending on the brand of chip used.
But the points above cover most of the errors for a few bios chips where the beep is constant.
So you should check all as I do not know exactly what brand of bios chip your board has Andre.