In the past couple of years, Linux has become well established as an alternative server and workstation operating system.

Professional users have discovered that Linux is a secure web surfing platform, as well. Linux might have just as many security holes as Microsoft operating systems, but SuSE, Knoppix, Red Hat and so on are not particularly vulnerable to virus attacks as they are not major targets for hackers.

On the other hand, Windows is indispensable when it comes to multimedia, especially video editing and DVD authoring. For office and image editing too, Windows is currently still in the lead. Consequently, many professionals use both systems.

In this feature, we're going show you the best methods for using two operating systems on one machine. If you're planning to make the switch, there's no real need to be concerned about problems resulting from using incompatible systems - Windows files can also be read in a Linux environment.

And these Unix-derived operating systems recognise and can now work with numerous Windows file formats. If need be, you can even run full-blownWindows applications such as Microsoft Office under Linux.

Linux And Windows together
There are at least half a dozen ways to use Linux and Windows together on one PC. The most popular of these is a parallel installation of both operating systems on a single hard disk.

Apart from configuring the boot manager, it's very easy to do, but does require a lot of hard disk space. This is particularly annoying if you've decided to turn your back totally on the Windows partition and find that you need 3-4GB of Microsoft files to occasionally view certain documents.

In this method, each of the two operating systems resides on its own partition. Current Linux distributions, such as Red Hat 9 or SuSE 8, take an existing Windows installation into account and integrate the Microsoft OS with the boot options. This does, however, require sufficient free hard disk space, in the form of unpartitioned areas or a free or unused partition of 3-5GB for a standard installation.

If there's enough space, the installer automatically works out a sensible partitioning scheme for Linux. Expert users can intervene if necessary to override the installer's suggestions and directly enter the desired partition sizes.

After a successful installation, you can simply select whichever operating system you wish to start from a menu at boot time. The Linux boot loader also allows you to specify boot options and pass parameters to the kernel.

Optimal partitioning
If you want to use both Windows and Linux as easily and securely as possible, you must ensure optimal partitioning. It's very important to consider how many partitions are needed, and what size each partition should be (the partitioning scheme). This will depend on your security requirements, the programs in use and the number of registered users.

It makes sense to put the Linux system directory (root) on its own partition with a mount point of '/' - this makes the recovery process following a system failure much easier. User programs are usually placed in the /usr and /opt directories, but personal files land in /home and temporary files are stored under /var.

Usually, it's not necessary to put the folders on separate partitions, with the exception of a separate swap partition.

If you want extra protection from mail viruses or spam, add /var on its own partition. The automatic partitioning included with well-known distributions assumes a division into root, /home, /var and swap. For beginners and those changing from Windows, it's sufficient to work with a system partition (/) and a swap partition.

Regardless of which distribution you opt for, Linux contains free partitioning utilities such as fdisk and cfdisk, which, although powerful, aren't the easiest tools for the novice to use as they don't have a graphical interface.

Most new users prefer the graphical partitioning tool that's normally included in each distribution's installer. For example, SuSE's configuration and installation tool, Yast, contains an easy-to-use partitioning program.

If you'd rather do the partitioning under Windows before installing Linux, you'll need to use a commercial utility such as Powerquest's Partition Magic.

Partitioning using cfdisk
The classic Linux partitioning tool is cfdisk, which is also used during a hard disk installation of Knoppix. You run this utility from the command line with the command 'cfdisk'. The program then lists all the detected hard disks complete with the partitioning information for each. Cfdisk can be controlled completely from the keyboard.

You select the various function buttons with the help of the cursor and Return keys. You can easily create new partitions on unpartitioned hard disk areas or delete existing partitions. If an existing partition is to be deleted, simply select it using the cursor keys, and then select the Delete command which you confirm with the Return key.

You create a new partition in a similar way, but instead of choosing Delete, choose New. For a minimal installation Linux requires a root and a swap partition. To create a new swap partition, select Primary to create a new primary partition. The size of the swap partition is dependent on the amount of available Ram, but you don't need more than 512MB in any case.

Specify the size either by entering the start and end sectors or the relative size in megabytes. The setting Beginning is recommended as the start sector for the first partition. Select Type 82 as the partition type for swap partitions.

The same method is used to create the Linux root partition. Again, use the options New and Primary to create a primary partition. The size you'll need is determined by the number of packages you want to install - if you're switching from Windows and working with a single Linux root partition, then 2-3GB will do for a default installation.

However, a partition of at least 10GB is recommended for day-to-day use with many multimedia files and a large number of applications. Naturally, you also have the option of using the whole free unpartitioned hard disk space. Choose partition Type 83 for the root partition.

Once the partitioning is complete, use the Write function to save and apply your changes. Partitions created like this can easily be used for a subsequent fresh installation of Linux.

To reduce the size of existing partitions, you'll need additional tools such as the free utility Parted (you can find this at the Linux search engine www.rpmseek.com or one of the many commercial Windows programs.

Using Linux files under Windows
Linux users can always access the partitions and data of a parallel Windows installation, and vice versa.

With the help of the free Windows-based utility Explore2FS, Windows users can read any partitions that use the Linux ex2fs filesystem. Explore2FS displays all available hard disks and shows any Linux partitions in separate Explorer windows.

You can then use drag and drop to access the data on the Linux partition. Explore2FS is free and works with Windows 95 to XP. The Explore2FS installer can be found here.

Windows data under Linux
Windows partitions can be accessed without any problems under Linux. During installation of Linux the operating system automatically recognises any existing Windows partitions and incorporates them in the Linux directory structure.

You can access data and programs in those partitions from the file manager or the command line. As all current Linux distributions automatically mount Fat16 and Fat32 partitions, and even make them available via a desktop icon, there's no real obstacle to file exchange between Linux and older versions of Windows up to ME.