We have been using this PHP accelerator (0.9.5), on multiple servers, for a long time. It's used on some high traffic sites without any problem.
Install:
a) Download a copy of eAccelerator that is compatible with your version of PHP.
This can be an issue with eAccelerator. Sometimes it can take a little time before the Windows binaries are available for the most recent version of PHP.
b) Copy a compatible eaccelerator.dll to your PHP extensions folder (like:D:\php\ext replace with your actual folder location).
Make sure the configuration directive extension_dir in your php.ini is properly pointing to your extensions folder.
Like: extension_dir = "D:/php/ext"
//将dll文件复制到D:/php/ext下．
c) Create a folder (with the appropriate permissions) for the temporary cached files.
For example: D:\temp\eaccelerator
//创建tmp目录　权限可写
d) Add the following to your php.ini (as the first loaded extension):
.
;extension=php_yaz.dll
;extension=php_zip.dll
//编辑php.ini 在extension=php_zip.dll之后添以红字部分

[eaccelerator]
zend_extension_ts="D:\php\ext\eAccelerator0952_5.2.3.dll"
zend_extension="D:\php\ext\eAccelerator0952_5.2.3.dll"
eaccelerator.cache_dir = "D:\temp\eaccelerator"
eaccelerator.shm_size="64"
eaccelerator.enable="1"
eaccelerator.optimizer="1"
eaccelerator.debug ="0"
eaccelerator.check_mtime="1"
eaccelerator.filter=""
eaccelerator.shm_max="0"
eaccelerator.shm_ttl ="0"
eaccelerator.shm_prune_period="0"
eaccelerator.shm_only="0"
eaccelerator.compress="1"
eaccelerator.compress_level="9"
eaccelerator.keys= "shm"
eaccelerator.sessions="shm"
eaccelerator.c
zend_extension="D:\php\ext\eLoader0952_5.2.3.dll"
;;;;;;;;;;;;;;;;;;;
; Module Settings ;
;;;;;;;;;;;;;;;;;;;
.
.
e) Restart your Web Server.You can see..


http://www.sitebuddy.com/PHP/Accelerators/eAccelerator_windows_binaries_builds