Wp-admin getting 500 Internal Server Error

Hi, suddenly out of nowhere my admin backend page has gotten internal server error and it is giving me the following error:

[08-Mar-2014 18:54:05] PHP Warning: file_exists() [function.file-exists]: open_basedir restriction in effect. File(C:\Inetpub\vhosts\domain.com\httpdocs/wp-content/plugins/http://www.domain.com/wp-admin/edit.php) is not within the allowed path(s): (C:disappointed:Inetpub/vhosts/domain.com\;C:\Windows\Temp\) in C:\Inetpub\vhosts\domain.com\httpdocs\wp-admin\menu-header.php on line 166

I'm currently running a cloud server and I know the temp folder is under C:\Windows\tmp

My php configuration is as follows:
safe_mode Off
PHP Version 5.2.17

Any clues?