I haven't seen that yet and I've done a lot of Mint installs.
Just for fun make sure the ram and hdd are ok.
Boot from a live cd of just about any linux distro
Run memtest 100%
Esc and boot to live cd desktop
Find Disks (aka Gnome-disk-utility)
All drives should say "Disk is OK"
Any bad sectors means replace the drive.
If all that is ok, I would burn my iso to a dvd and do a "something else" Install
I'd make a new partition table first. Hopefully that would clear out the partition section of the first 512 bytes of the boot sector. But if I had a boot sector virus, I'd have had to write zeros to that area.
That would be done by writing
sudo dd if=/dev/zero of=/dev/sda bs=512 count=1
in terminal. But that's usually not necessary, and I'd do that in a gparted live cd.
Back to the fresh install: After making a new partition
On the install screen
right under - + change
Device for bootloader installation
Hit the arrow on the right
pick your target sda not sda1
You want the grub to be in the boot sector of the drive.
If you're dual booting You can load the linux /, swap, and /home in an extended partition.
If your doing a fresh install in a Win8 computer, You may have to disable secure boot in bios. This is a subject with which I am not familiar.