Hi everybody, I need help installing WAS 6.1 on Windows xp sp3

I'm trying to install WPS 6.1 on windows XP sp3 (full installation with WAS, cd images from IBM site, see http://www-01.ibm.com/support/docvie...id=swg21363952).

When WAS installation starts, a message appears: XP SP2 missing, installation may fails.

I proceed (sp3 contains and extends sp2, I think), WAS installation finishes succesfully.
Then during step 5 of Portal installation, I receive this error:
[wplc-modify-java-virtual-machine] [11/07/09 17:24:59.921 CET] The system cannot find the specified file, either the filename is too long on Windows system or run out of file descriptor on UNIX platform.
java.io.FileNotFoundException: d:\IBM\WebSphere\wp_profile\wstemp\anonymous125761 1099781\workspace.repositoryContext (Impossibile accedere al file. Il file ? utilizzato da un altro processo.)

My pc is new, no addictional software, I stopped antivirus and google desktop before installation, I entered with user with administrator profile and "act as system" permission, none of the installation file is read-only
I installed on "d:\ibm" (a short path) and the node name as no special char or hyphen in it

Part of stack trace follows (in attached file).