Linux or unix Live cd

There are a number of live CD's and none as far as I know will delete any thing unless you do it your self. These load into memory creating a virtual drive, it dose not use the O/S to work. And the memory is dynamic, it is not saved after it is used or after a reboot.
Here are some links to down loadable Live CD's and read the how to's before using them.
http://www.nu2.nu/pebuilder/
http://www.ultimatebootcd.com/
http://www.knoppix.org/

Everything that you load from any Boot loads into a Virtual Drive in RAM. That can be a Windows 98 Boot Floppy or a Live Linux and as Ram is Dynamic it disappears once the power is removed so it has no effect on the already installed OS.

Now it depends on what you want to do as to what is the best Live Linux to use. If you want to runs some Diagnostics then the Ultimate Boot CD is the best option as it has a lot of very good diagnostic tools.

If you want to remove a Password that is preventing you accessing Windows or just read a NTFS Drive Knoppix Live is your best option and if you just want to test the hardware to see if it's working any Live Linux will do the job without affecting any stored data at all. Many of them will even fail to see a NTFS Partition of Drive so with those loaded you can not possibly do any damage to the OS on your existing HDD/s.

If you have a problem that you are unsure of like lets say one letter continually appearing whenever you open a field in Windows it would be a good idea to load a live Linux open Open Office Word Processor and see if the problem persists if it does you know that you have a hardware problem that requires attention or replacement and it saves you wasting hours attempting to find a software problem with Windows.

Col

Almost any, but I personally would use Simply MEPIS (it is what I'm currently using) or Ubuntu - the original disc comes as a Live CD that you run and when you decide you want it on your system you select the option to intsall it to the hard drive.

Live cds do in fact use the PC's RAM. The RAM will return to normal once the cd is no longer in use. If you save anything while the live cd is in use it is saved into RAM and will be lost once you leave the live cd program. Hard drives are not loaded in live cds...usbs can be used though.

well it depends on what you looking for .are u looking to learn about linux or security penetration .i recommend ubuntu or slax if u wanna learn but u have to read some linux books too and u can find thos in amazon .live linux DOES use your RAMS because it load all the modules into the ram and work from there .there will be no files downloaded into u drive unless u instal it .your rams get back to normal when u r done and restart the machine into windows .