I had to buy a new PC, which came with Windows 7 (another piece of MS crapola IMO). I have a lap-top with XP and prefer it over Win. 7. I also use Ubuntu (Linux based). I am sticking with Ubuntu 10.04 (or 10.10). It runs a lot faster than Windows even using "virtual disks". The new Ubuntu releases also made changes (that Win. 8 is "copying"). They came out with a new GUI called Unity. It provides a common I/F for Android based tablets (and any future Ubuntu based tablets). I don't like the Unity I/F - while not exactly Win. 8 functionally, it has sufficient changes that I find unsatisfactory. I installed VirtualBox on my Win. 7 system and I can install one or more other op systems - although I never could get the preview version of Win. 8 to install. I have tried Linux Mint 12 (Ubuntu-based) after seeing a lot of recommendations by others on the internet. I can say I ended up disappointed. I did try different desk-tops (you can install them like any other application) - select the one you want when you log-on. A couple of them give a similar look and feel, but have some missing features that I liked - same holds true with Win. 7 vs XP. One Linux release that impresses me is Zorin_OS (also Ubuntu-based 10.04 or 10.10). Once installed, you can actually choose a GUI feel that looks a lot like Win. XP or Win. 7 (or classic Ubuntu). I recently downloaded "Classical Shell" for Win. 7 - I haven't installed it yet, but it says it makes the desktop look more like XP. I will find out. The basic problem is with these new I/Fs, some of the old applications don't work due to changes made. Another reason t use something like VirtualBox or VMWare - you can install XP (or older Ubuntu versions) and run your old apps. Another thing I use is DOSBox. It is free and I can run "old DOS" apps that may or may not have run on XP and won't run on Win. 7. It takes a little bit of set up (directories are renamed to "hard drives" and PATH may require extra entries).
BTW, if you are interested in Ubuntu, I'd suggest you download 10.04 (or 10.10) before the end of the month when they come out with 12.04. Every 2 years, they come out with a Long Term Release (LTR). Ubuntu 10.04 was a LTR and 12.04 will be the next LTR (then 10.04 will no longer be available from Canonical - although a Google search will probably find it on some other site). You can download it, burn it to a CD and actual run it from the CD (to try it - any updates would be lost and any of your data would have to be saved to a USB stick or the like). You can also do a Wubi install. I did that on my XP lap-top. You run the Wubi.exe file on the CD and it installs it into a Windows directory. It does add a line to the XP boot.ini file so when the Windows directory install is complete and you reboot, you will see a choice to boot into XP or Ubuntu. It also has an uninstall "exe" file like most Windows apps. I used that method initially as I found it a good way to learn more about Linux and still do my XP stuff without messing around with dual-booting and partitioning.
A lot of people who who tried the Ubuntu distro of Linux ended up switching to it permanently instead of putting up with all the MS changes. One final point, it also has an application called WINE (Windows Emulator). It will run a lot of Windows application (exceptions for now are Photoshop and a few others). WINE keeps improving over time.
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