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.

Problems do arise, however, when exchanging data with NTFS partitions, as used by Windows NT/2000 or Windows XP. Linux does offer support for this in the form of a suitable driver, but this driver does have a few shortcomings which might, under some circumstances, damage the file system.

Because of this, it's better if you use the bundled Linux kernel-based NTFS driver in read-only mode. Fortunately, write access to NTFS partitions is turned off by default in this driver.

Windows under Linux
Anyone wanting to use Windows applications under Linux won't able to avoid the emulator Wine. It has a reputation for being complex and immature, but in this section we'll show you what Wine can really do.

Many Linux fans only leave Windows on their hard disk because they want to continue to use certain applications, but some do not want the oversized OS at all. You can run many Windows programs directly under Linux, with the help of Wine, the most widely distributed Windows emulator. It simulates almost the entire Application Programming Interface of a Windows environment.

In addition, Wine provides all important OS functions as well as system calls via its class system. Ideally, a Windows application will not even notice it is running under Linux. The system itself lives on a virtual system partition. Optionally, you can store genuine Windows libraries (DLLs) alongside those provided by Wine, in case you have problems with Wine's native libraries.

When using Wine you'll find that installation routines of many programs work and it's possible to install simple Windows programs directly to the virtual system partition. Some experts have perfected this to persuade more complex applications, such as Word 2000, to co-operate. However, this is complicated and unreliable.

In general, to start a Windows program under Wine, simply use a terminal window and the command: wine [path and program name]. For example, wine /home//wine/C/Program/winword.exe.

Multiple versions of Wine
There is not just one version of Wine, but a whole series of variants. Each current Linux distribution includes a basic Wine package, which can be customised using a graphical configuration front end.

However, up-to-date versions of Wine are different and must be configured entirely from the command line. One alternative is the commercial product, WineX. This expanded version of Wine works with newer Windows programs based on DirectX.

Wine's limits
A Windows emulator might be a technically interesting alternative, but is still no substitute for a parallel installation of a Windows system. Hardware-specific software like drivers or system utilities can't be used with Wine under Linux.

You can use most current hardware, such as printers, joysticks or modems, via emulated interfaces, but if a printer requires a special Windows driver that has no Linux equivalent, it can't be used under Wine. Multimedia applications that rely on Windows codecs also pose difficulties, so Windows users who hanker after a permanent changeover should keep an eye on developments.

Microsoft Office under Linux
If you primarily want to run Microsoft Office under Linux, the best option is the Crossover Office package. Costing about £40, it is already included in SuSE Linux Office Desktop and Lindows. Crossover is based on Wine and makes it possible to install Word, Excel and Powerpoint under Linux.

There seem to be no problems with this process and Crossover Office is stable. However, it isn't possible, using version 1.03 (still distributed), to use Crossover Office to install Microsoft Access under Linux. The new version, 2.0.1, supports Office 97, 2000, XP and Adobe Photoshop 7.

Crossover Office in use
Setting up Crossover Office and the subsequent configuration of Office under Linux is easy. To install Crossover Office 2 you need the relevant installation script. You can get a free trial version from Code Weavers. Both the trial and full version, which costs $59.95 (£38 approx), are installed by executing a virtual script under KDE or Gnome.

Crossover Office setup can be carried out as root or as a standard user. The administration mode has the advantage that all system users can load Windows applications via Crossover Office. On the other hand, if Crossover Office is installed in user mode then only that user is permitted to load Windows applications.

After calling the script, the Crossover Office graphical setup routine appears. Under Global Options, enter the directory where the package is to be installed. Accept the preset, which is your own home directory, then click on the Begin Install button.

After installation use Configure Now to configure the applications. The setup area's main window contains an overview of all the Windows applications which are already installed on the system.

To configure further Windows programs, a click on the Install button is enough. You can then choose from a list of supported Windows programs which ones you want to install.

Highlight the relevant program and click the Next button. You must, of course, have the original CD. If you want to install an application which is not listed, tick the Install unsupported software box and specify the directory where the installation data is found.

Generally, the installation can be finished by clicking the Next button in all further dialogues.