Centos – ISO2USB vs Universal USB Installer vs LinuxLive USB Creator for a CentOS 5.9 install

Update: Microsoft has created the Windows 7 USB/DVD Download tool to make this very easy.

I used this guide as a set of directions - http://kurtsh.spaces.live.com/blog/cns!DA410C7F7E038D!1665.entry

1. Get a USB Thumbdrive between 4-32GB.

If the drive is larger than 32GB, Windows cannot format it as FAT32, so an alternate utility must be used. Windows can still read FAT32 partitions larger than 32GB, though some devices cannot.

2. Run cmd.exe as administrator and enter the following commands followed by Enter

1. diskpart
2. list disk
3. select disk # (where # is your USB drive as determined from step 2)
4. clean (This step will delete all data on your flash drive!)
5. create partition primary
6. active
7. format fs=fat32 quick
8. assign
9. list volume
10. exit
11. bootsect.exe /nt60 F: /mbr (where F: is the drive letter of your USB drive as reported by list volume)

3. Copy the Windows files from the ISO or other source using robocopy

robocopy.exe E:\ F:\ /MIR

where E:\ is the source and F:\ is the destination. Drag-and-drop or copy/paste can also be used, if you know what you're doing.

Configure your PC to boot from the USB drive

In some machines the USB thumbdrive will appear to the BIOS as any other hard drive. You need to muck with the boot sequence to place the thumbdrive higher in the boot order than the local hard drive.

Note that after you do this you might want to reset the boot order in order to ensure that BitLocker doesn't detect boot changes based on the fact that the thumdrive is missing if it was there when you encrypted your drive.

Ubuntu now includes a "install to USB" option in the system menu. This is your best bet and does not require trying to cram a large file onto the stick - instead, files are stored "normally", which means you'll be able to get around the 4Gb barrier.

Install gparted to assist with this:

sudo apt-get install gparted
sudo gparted

If the GUI method doesn't work, try directly formatting through the command line instead.

The file size limitation still applies, so if you plan on having large files, Ext2 is still your best choice. Format it as Ext2 and then use the provided tool to do the install.

If you're stuck in a chicken-and-egg situation (only have a Windows install to work with but no live Linux install) you could burn the ISO to a CD, boot the CD, download and install the partition program, run it to partition the stick, and then run the USB install from there.