You might think it impossible for your new rig to actually run out of memory when copying or moving data, but it appears that Microsoft’s latest operating system, Windows Vista, can do so when a user tries to copy 16,400 files or smaller groups of files that add up to 16,400 between reboots – regardless of your memory size. The problem worsens when users are running Kaspersky Anti Virus 6 or 7, but it is not the software that is causing the problem. According to Microsoft:

This problem occurs because of a memory leak in the Windows OLE component. This memory leak is triggered by the way that Windows Explorer deals with the extended attributes of the files.
Following the “Out of Memory” message, you can expect plenty of other errors to occur including menus and tabs disappearing within the Windows environment and even reboots and BSODs (Blue Screens of Death) errors. Apparently a fix was scheduled for SP1 but didn't make it. Instead, you have to submit a request to Microsoft Online Customer Services to obtain the hotfix for the problem.