=== What is it? ===
Bitdefender Rescue CD is a bootable Linux operating system, with a built-in virus scanner by Bitdefender. It has a simple Graphical User Interface (GUI), which is the standard visual point and click interface, with a cursor, icons, etc. This is the easiest interface for most of the ordinary computer users, so they wouldn't struggle to figure out how to use this software.
Bitdefender antivirus can be updated in live boot mode, and you'll notice the virus scanner works much faster than it would in Windows. This is because Windows unnecessarily drains much of your computer's hardware resources, while a live boot only uses the bare minimum, so it leaves most of the resources available to carry out more processor hungry tasks.
As with any bootable CD image, it can be loaded to a bootable USB drive. There are many open-source tools to assist with this task. You may find a few at pendrivelinux.com.
=== Why USB boot? ===
I recommend booting from a USB drive for a number of reasons. If you burn it to a CD, the burn process may fail, or the CD may fail to boot if it's scratched or the data has become unreadable due to one of the many other problems with optical media. If there's an error putting the data onto a USB drive, you can simply retry, and you won't have to throw it away. You can also update the antivirus signature database, and this update will remain in the USB drive, while a CD doesn't have that capability. Optical drives such as CD and DVD have much slower read speeds than USB; their speeds are nowhere near as fast as USB2, and USB3 interface is much faster USB2. The faster the storage medium performs, the faster the program loads to memory. This is essential for high speed performance.
As you'll notice on pendrivelinux.com, USB's can easily be made to multi-boot. So, you won't be buying many USB flash drives to boot many different systems, all you need is one disk with a high enough capacity for all the bootable files.
USB boot isn't supported by many older computers, and some lower grade PCs. In this case, you'll have to make do with burning the image to CD.
=== My experience with Bitdefender Rescue CD ===
I've only been using the Bitdefender Rescue CD for a few years, but have found it the most useful of all the free antivirus boot disks. I've used others such as Kaspersky, which is also very good, but Bitdefender can be easily installed onto a Linux operating system. The other difference is Bitdefender Rescue CD starts up faster than Kaspersky, and doesn't require 'startx' to start-up the GUI interface. Selecting files and folders for scanning is as easy as any dialogue box within Windows, or in any other simple GUI based system.
To run a virus scan, you can choose the location of what you want to scan, or you can choose to scan everything. The scanner engine starts with the application and after updates, depending on which version of the Rescue CD you have. I've never had problems with the Rescue CD, but if you're running it from a "very high capacity" USB drive you purchased from Ebay; you may find some problems. This is because many of those very high capacity USB drives are counterfeit oversized.
Due to oversizing the storage volume, the performance of the hardware is massively reduced. You can test your USB drive's performance using any hardware benchmarking utility, such as H2testw. I bought a few USB drives off Ebay, which have this problem. The advertised device capacities are 32GB and 64GB, but the real capacities are 4GB and 8GB. The eightfold difference to the real volume size has roughly the same percentage of decrease in performance, so a 32GB fake size USB2 drive writes at about 3MB/s, instead of about 24MB/s.
Other than the USB flash drive counterfeit oversize, I've never faced any other performance problems with Bitdefender Rescue CD. That itself isn't a problem with the software, as I've explained. So, I wouldn't include that when giving the star ratings.
I believe from personal experience, that Bitdefender rescue CD's virus scanner is faster than Kaspersky's alternative. Whether one has better quality of virus checking, isn't something I would know much about. I don't normally bother with reading the virus scanner logs, reports or other related scan data.
To close the program, the procedure is like any window based program with a clear exit button, and ability to close using the standard shortcut Keys Alt+F4. You can restart the computer, remove the bootable disk and load whichever operating system you normally use.
=== My Conclusion ===
Bitdefender Rescue CD is a free bootable GUI based virus scanner, which can be updated in live boot mode. The scanner runs faster, because it's not running alongside a massive processor hungry operating system. I recommend you use a bootable USB if possible, and if you have any performance problems, test it with a free benchmarking utility. When all other antiviruses fail to remove a stubborn threat, I've found this to succeed. You can download the bootable iso image from download.bitdefender.com/rescue_cd. I prefer the free software such as this, rather than paying £50+ for an expensive, slow boot disk. I give this a five star rating, actually about four and a half, but rounded to five, because it performs very well and removes all the known viruses.
=== To sum up ===
You might want to get this to remove stubborn viruses, because it's probably the best. I prefer running it off a USB flash drive, because it allows for better performance and update capabilities than a CD. Most importantly it's free.