You need GRUB4DOS. Despite the name, it doesn't need DOS.
You can download it in Tiny Core using the App Browser, or using this command:
tce-load -wi grub4dos
When your stuck with an Linux distro or Windows, so you'll need to download the package:
https://code.google.com/p/grub4dos-chenall/downloads/list
On Windows you'll also need another tool to write the first stage boot loader. It's in the package grubinst-1.1-bin-w32-2008-01-01.zip, available here:
http://download.gna.org/grubutil/
1. Format the USB stick with a partition using FAT16/32, NTFS or Ext2/3 (not Ext4). Ext2 is ideal for USB drives, and ext3 is ideal for hard drives.
You create the first stage boot loader on a Linux system running bootlace.com:
./bootlace.com --time-out=0 /dev/of_usb_stick
(like /dev/sdb, not /dev/sdb1)
2. Copy the file “grldr” at the root of that partiton. And copy the tinycore-iso file to that same place and rename it to “tinycore.iso”.
3. Create a file “menu.lst” at the same place containing this:
find --set-root /tinycore.iso map --mem /tinycore.iso (hd32) map --hook root (hd32) chainloader (hd32)
After these steps, booting from the USB stick should give you the familiar boot screen from Tiny Core Linux.
This info from http://forum.tinycorelinux.net/index.php?topic=10430.0 with minor modifications.
Tinycore may also be installed without a CD or DVD drive using the multicore iso and UNetbootin.
To install Tinycore using this method, follow the instructions on the UNetbootin website.
With isohybrid one has a trivial pendrive installation.
No installation program needed.
dd if=multicore-current.iso of=/dev/sdX
Just be absolutely sure that you have specified the correct target for the output file of=
Note: only the multicore.iso has this feature.
However it is simple to isohybrid the other isos, e.g.
isohybrid tinycore-current.iso
isohybrid is provided by the syslinux.tcz extension.
This info from: http://forum.tinycorelinux.net/index.php?topic=11017
Note: If you use this method, and later want to use the drive for something else, you may need to repartition the drive. This can be done with GParted, which can be installed in Tinycore, or run from Parted Magic. You may need to delete the existing partition and create a new one.
Depending on which method you use, and exactly how you install it, you may want to reinstall it using one of the installers.
For example, if you use UNetbootin, it installs to a FAT32 filesystem, whereas Tinycore should ideally be installed to a Linux filesystem. Also if you install Tinycore to a USB drive using the Tinycore installer, the USB drive is identified using UUID, whereas it is not when using UNetbootin.
You can reinstall Tinycore using one of these methods