By default a client can’t upload files in plesk file manager larger then ~30MB . Unfortunately we have to let them upload bigger files because they like to use the  archive “uncompress” feature from file manager.
The error received in plesk is:
HTTP Error 404.13 – Not Found
The request filtering module is configured to deny a request [...]

My windows 7 beta was expired so I searched for a solution to “repair” it. Bellow is what I have found. It took some time to upgrade (about 1 hour) but worked flawless for me.  no data loss , but just to be sure make a backup of your important data first
Here’s what [...]

It happened that webmail from plesk windows just opened a page with error 503 , service unavailable. In our case it was horde webmail with plesk 8.6  IIS7 on windows 2008. Restarting whole IIS did not help.
Unfortunately I did not find too many docs related to it so find out from Parallels that webmail is [...]

To configure PEAR bundled with PHP the following steps need to be completed:
1. Launch command prompt.
2. CD “%plesk_dir%Additional\Php\”.
Note: The folder can be different – e.g. in case of using PHP5.
3. Execute go-pear.bat and follow the on-screen instructions.
4. Add the path to the newly created pear.bat file into the PATH system variable after installation and reboot [...]

just execute folowing in cmd prompt (run as administrator):
c:\windows\system32\inetsrv\appcmd.exe migrate config “site-name/app-folder”