Munich - Windows 7 has arrived to greater accolades than any other operating system from Microsoft before it.

Even so, it seems unlikely to inspire waves of users to rush out to buy a computer with the operating system already installed or simply wipe out an existing version of Windows on a computer that's running just fine. Fortunately, there's no need to do either, since Windows
7 can be installed in parallel with your current operating system.

First you must decide whether to opt for the Home Premium, Professional, or Ultimate versions of Windows 7. One significant drawback for the Home Premium option: no pre-installed network backup functionality, which comes built-in with Professional and Ultimate. Only Ultimate offers the BitLocker hard drive encryption. "The 'BitLocker to Go' function is new," says Microsoft's Daniel Melanchthon.

The Home Premium version is nevertheless probably enough for the average user. "It contains all of the core functions and is complete when it comes to multimedia functionality," writes author Wolfram Gieseke in his new book, Windows 7.

A bit of preparatory work is required to install Windows 7 parallel to an existing Windows setup. A segregated portion of the hard drive must be set up from the existing one to house the new operating system. If one imagines the PC as being a hotel, then it makes sense that different guests staying at the hotel will want their own rooms. The "rooms" in this case are known as partitions.

Computers purchased with Windows Vista pre-installed are likely to find just one partition in place. That means that a new one must be created for Windows 7 - a process that reduces the size of the current partition. The newly created space is then formatted and readied for use by the new operating system.

For systems running Vista, this process is relatively painless, since the Windows 7 predecessor comes with all the tools it needs. The data on the previous partition is not affected as long as it's not made so small that insufficient storage space is on hand. Users should always make a backup beforehand. The partition for Windows 7 should not be smaller than 20 gigabytes, Gieseke recommends.

Setting up a parallel installation of Windows 7 and Windows XP is a bit more laborious. Because XP includes no built-in software for changing the partition, users must install an extra tool. The 30 dollar purchase price is especially painful since it is likely to be used only once or twice. One cheaper option: scouring computer magazines for full versions.

Once a partition has been freed up, the installation process itself can get underway. Launching the installer involves booting the computer with the DVD as the boot drive or launching the program from within a running system. The program offers the option of upgrade or "user defined."

The latter choice includes parallel installations or complete new installations of Windows 7. A list of partitions is then shown, including the empty one intended for Windows 7. One more click on "Continue" and the data is copied to the hard drive and installed.

The computer restarts several times during the installation process. Precisely how long the procedure lasts depends primarily on the speed of the computer. Reasonably current computers can finish the process in around a half-hour.

The easiest variant is installing Windows 7 onto a "bare" hard drive. A real upgrade that simply swaps in Windows 7 and leaves the data in place is only possible with Vista. "And Service Pack 1 has to be installed," explains Axel Vahldiek from German computer magazine c't. XP users will need to undertake a complete new installation. (dpa)