A new version of the Windows compatible ReactOS has been released

ReactOS is a Free Community Opensource Collaborative Compatible Free operating system. Imagine running your favorite Windows applications and drivers in an open-source environment you can trust. That's ReactOS. Not just an Open but also a Free operating system.

Our Features
Lightweight
500MB HDD and 96MB RAM

From Scratch
This is not Linux mimicking Windows.

9,000,000+ lines of code
And growing!

100+ devs
Have contributed along the years.

Styles
Classical and ReactOS Lautus styles.

Tons of Open Modules
From Games to Drivers: Open Source and Free.

Ready to Install...
Download our BootCD.

...or to Try.
Download our LiveCD.

and more...

Changelog-0.4.9
Kernel:

CC: Finalized read ahead and lazy writing implementation. Fixed lots of bugs and deadlocks. Fixed random behaviours. (Pierre Schweitzer)
CC: Fixed lots of VACB leaks. This fixes many big operations. (Pierre Schweitzer)
CC: Fixed a race condition. With fixes in FAT32 driver, ReactOS can be built on ReactOS. (Pierre Schweitzer)
MM: Fixed a page mapping issue causing corruptions. (Thomas Faber)
KE: Fixed a loop indefinitely trying to figure out CPU frequency. This eliminates a boot delay. (Thomas Faber)
IO: Implemented support for reserve IRP. This is critical for low memory situations. (Pierre Schweitzer)
PNP: Minor enhancements. (Hermes Belusca-Maito)
FSRTL: Fixed a nasty typo prevented freeing memory. (Pierre Schweitzer)
Lots of improvements to 1st stage setup: Added support for some navigation keys. Improved installation path checks and entering partition size. (Eric Kohl)
Win32 subsystem:

win32k/ntuser: Fixed some regressions. (Thomas Faber)
win32k/ntuser: Fixed some menu issues. (Thomas Faber)
win32k: Filled a gap that affected window stations. This prevents system from messing up. (Hermes Belusca-Maito)
win32k: Some fixes for font substitutes. (Mark Jansen)
usersrv: Hard errors are sent to desktop now; various hard error improvements. (Hermes Belusca-Maito)
Drivers:

i8042prt: Fixed keyboard bug on Lenovo ACPI. (Nikita Krapivin)
usbport: Merged transaction translator support. This is crucial for various USB 2.0 controllers, and will fix lots of boot problems with USB enabled. (Vadim Galyant, Colin Finck)
fastfat: Fixed directory leaking. (Pierre Schweitzer)
fastfat: Implemented write IOs deferring. This fixes issues occuring when copying large files. (Pierre Schweitzer)
fastfat: Implemented support for stack overflow in read operations. (Pierre Schweitzer)
fastfat: Fixes for autochk. (Pierre Schweitzer)
fastfat: Rewritten support for dirty volumes. This will greatly reduce file corruptions, and trigger repairing. (Pierre Schweitzer)
fastfat: Fixed race conditions on high IO operations. (Pierre Schweitzer)
Shell:

Fixed locking and unlocking taskbar. (Giannis Adamopoulos)
Implemented showing hard error balloon. (Hermes Belusca-Maito)
Fixed some icon problems. (Hermes Belusca-Maito)
Fixed some key shortcut issues in Command Prompt. (Hermes Belusca-Maito)
System DLLs:

hal: Fixed two stack overflows, one in interrupt handlers. (Thomas Faber)
ntdll/ldr: Added initial verifier. (Mark Jansen)
advapi32: Some improvements to services. (Hermes Belusca-Maito)
advapi32: Fixed service stopping sequence. (Eric Kohl)
kernel32: Added Vista exports. (Timo Kreuzer)
User-mode DLLs:

shell32: Implemented right click drag menu. (Giannis Adamopoulos)
shell32: Fixed some more memory leaks. (Giannis Adamopoulos)
shell32: Improved folder type names. (Mark Jansen)
shell32: File extensions (and associations) can now be managed. (Katayama Hirofumi MZ)
comctl32: Finally synced with Wine Staging 3.3. This is expected to fix many issues. (Giannis Adamopoulos)
beepmidi: Fixed busy wait when no notes are playing. (Thomas Faber)
windowscodecs: Fixed stack corruption when showing PNGs. (Thomas Faber)
afd: Some bugs are fixed in socket connection. (Mark Jansen)
msvcrt: Various fixes to file (descriptor) functions. (Thomas Faber)
apisets: Added apiset DLLs from Wine for forwards application compatibility. (Mark Jansen)
zipfldr: Added ZIP shell extension along with zlib library. (Mark Jansen)
setupapi: Some more progress. (Eric Kohl)
syssetup: Added more pages for settings of various hardware in 2nd stage setup. (Eric Kohl)
Commands and utilities:

rapps: Replaced extract with FDI for handling cabinet files. (Alexander Shaposhnikov)
services: Update a driver's status properly. (Eric Kohl)
services: Fixed service stopping sequence. (Eric Kohl)
sc: Many improvements to this command. (Eric Kohl)
net: Many improvements to this command. (Eric Kohl)
sndvol32: Added volume tray dialog. Added small master dialog. Fixed various dialogs. (Eric Kohl)
drwtsn32: Various improvements to Dr. Watson. (William Kent, Mark Jansen)
dhcpcsvc: DHCP client can be stopped now. (Eric Kohl)
tftpd: Added Open TFTP Server. (Hermes Belusca-Maito)
eventvwr: Major improvements for Event Viewer. Added command line support. (Hermes Belusca-Maito)
mspaint: Fixed crash on zoom-out. (Stanislav Motylkov)
mspaint: Fixed canvas disappearing, a right-click bug and persistently saving file as Unnamed. (Benedikt Freisen)
clipbrd: Improvements in Clipboard Viewer. (Joachim Henze, Hermes Belusca-Maito)
Tasks:

User-mode DLLs are synced with Wine Staging 3.3. (Amine Khaldi)
Various x64 boot fixes have been made. More work is needed to get x64 port running. (Timo Kreuzer)

  ReactOS 0.4.9 released