Installation of xwiki-enterprise-installer-windows-2.6-rc-2.exe does not work

I get xwiki-enterprise-installer-windows-2.6-rc-2.exe from XWiki.org website
http://www.xwiki.org/xwiki/bin/view/Main/Download

Just after starting XEM instance, I ve got the following error:

Accès refusé.
2010-11-26 17:07:55.890::INFO: Logging to STDERR via org.mortbay.log.StdErrLog
2010-11-26 17:07:55.992::INFO: jetty-6.1.21
2010-11-26 17:07:56.042::INFO: Deploy C:\Program Files\XWiki Enterprise\jetty\c
ontexts\xwiki.xml -> org.mortbay.jetty.webapp.WebAppContext@291aff

{/xwiki,C:\Pro gram Files\XWiki Enterprise\jetty/../webapps/xwiki}

2010-11-26 17:07:56.047::INFO: Deploy C:\Program Files\XWiki Enterprise\jetty\c
ontexts\root.xml -> org.mortbay.jetty.webapp.WebAppContext@186db54

{/,C:\Program Files\XWiki Enterprise\jetty/../webapps/root}

log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: xwiki.log (Acc+¿s refus+®)
at java.io.FileOutputStream.openAppend(Native Method)
at java.io.FileOutputStream.<init>(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)
at org.apache.log4j.FileAppender.setFile(FileAppender.java:294)
at org.apache.log4j.RollingFileAppender.setFile(RollingFileAppender.java
:207)
at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:165)
at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:3
07)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.j
ava:172)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.j
ava:104)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigura
tor.java:809)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigura
tor.java:735)
at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyC
onfigurator.java:615)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurato
r.java:502)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurato
r.java:547)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionCon
verter.java:483)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
at org.apache.log4j.Logger.getLogger(Logger.java:104)
at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.jav
a:289)
at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:1
09)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Sou
rce)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.apache.commons.logging.impl.LogFactoryImpl.createLogFromClass(Log
FactoryImpl.java:1116)
at org.apache.commons.logging.impl.LogFactoryImpl.discoverLogImplementat
ion(LogFactoryImpl.java:914)
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactory
Impl.java:604)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactory
Impl.java:336)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactory
Impl.java:310)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)
at org.xwiki.component.logging.CommonsLoggingLogger.<init>(CommonsLoggin
gLogger.java:38)
at org.xwiki.component.embed.EmbeddableComponentManager.<init>(Embeddabl
eComponentManager.java:62)
at org.xwiki.container.servlet.XWikiServletContextListener.contextInitia
lized(XWikiServletContextListener.java:54)
at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.
java:548)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.jav
a:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:
517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467
)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection
.java:152)
at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHan
dlerCollection.java:156)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection
.java:152)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:
130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.xml.XmlConfiguration.main(XmlConfiguration.java:985)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.mortbay.start.Main.invokeMain(Main.java:194)
at org.mortbay.start.Main.start(Main.java:534)
at org.mortbay.start.Main.start(Main.java:441)
at org.mortbay.start.Main.main(Main.java:119)
2010-11-26 17:08:00.415::WARN: failed org.mortbay.jetty.NCSARequestLog@5878d2:
java.io.FileNotFoundException: C:\Program Files\XWiki Enterprise\jetty\logs\2010
_11_26.request.log (Acc+¿s refus+®)
2010-11-26 17:08:09.643::WARN: failed RequestLogHandler@159d87f: java.io.FileNo
tFoundException: C:\Program Files\XWiki Enterprise\jetty\logs\2010_11_26.request
.log (Acc+¿s refus+®)
2010-11-26 17:08:09.644::WARN: failed HandlerCollection@1949f78: java.io.FileNo
tFoundException: C:\Program Files\XWiki Enterprise\jetty\logs\2010_11_26.request
.log (Acc+¿s refus+®)
2010-11-26 17:08:09.645::WARN: Error starting handlers
java.io.FileNotFoundException: C:\Program Files\XWiki Enterprise\jetty\logs\2010
_11_26.request.log (Acc+¿s refus+®)
at java.io.FileOutputStream.openAppend(Native Method)
at java.io.FileOutputStream.<init>(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)
at org.mortbay.util.RolloverFileOutputStream.setFile(RolloverFileOutputS
tream.java:243)
at org.mortbay.util.RolloverFileOutputStream.<init>(RolloverFileOutputSt
ream.java:164)
at org.mortbay.jetty.NCSARequestLog.doStart(NCSARequestLog.java:428)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.jetty.handler.RequestLogHandler.doStart(RequestLogHandler
.java:117)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection
.java:152)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:
130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
50)
at org.mortbay.xml.XmlConfiguration.main(XmlConfiguration.java:985)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.mortbay.start.Main.invokeMain(Main.java:194)
at org.mortbay.start.Main.start(Main.java:534)
at org.mortbay.start.Main.start(Main.java:441)
at org.mortbay.start.Main.main(Main.java:119)
2010-11-26 17:08:09.693::INFO: Started SelectChannelConnector@0.0.0.0:8080