If you are like me then you have very little command line experience and are having trouble or have had trouble in the past installing BT4 on to a USB drive. This is a method for installing BT4 on to a USB drive with the options of making it persistent and virtual.
You will need a neat little windows program called LinuxLive USB Creator (LiLi for short). It can be downloaded for free form this URL http://www.linuxliveusb.com
After installing the program there are only five easy steps, all of them are performed with a mouse.
Step 1: We have to tell the program where to find the USB drive. Click on the drop down box and select the drive you want. I recommend an 8GB or larger drive but if you are not going to make it persistent then a 4GB should be fine.
Step 2: Select the linux image. I say linux image and not BT4 because it supports many different distros. To install BT4 the easiest way is to download the image you want and then select the icon labled "ISO/IMG/SIP". It can be installed from a CD or downloaded right from the program as well. A neat feature is that once an image is selected LiLi checks the image to see if it is supported and is not corrupted.
Step 3: Here is where an actual decision must be made. Do you want persistence? Don't get scared this is easier than any other form of persistence. Persistence is good because it save changes that you make to the USB drive unlike a live CD. This is nice because you can install programs and drivers that you might need for some computers. It can be bad if you are learning how to use say the command line and frequently blow things up. LiLi does not remove the option to boot up in live mode but just adds an option to boot with persistences. So if you have the space don't hesitate. If you want it grab the slider and pull it over as far as you want (max is 4GB).
Step 4: We are almost done. This step is just some options.
First if you have a large Thumb Drive then not all of it will be used by BT4. You will inevitably place other files on to it. To prevent accidentally deleting all your hard work LiLi will hide the BT4 files on the drive.
Secondly I recommend going ahead and formating the drive before installation. This option is not checked by default probably to avoid a lawsuit because somebody had some file worth millions on the drive and didn't know that formating wipes the drive. So I must warn you now that this step essentially DELETES everything. BACKUP the files you want to keep.
This last option is really neat. LiLi can install Oracles virtual box on to the drive and then makes a virtual machine out of BT4. This makes it so BT4 can be run with out even rebooting the computer but still leaves that option available.
Step 5: Click the lightning bolt to install.