Those temp files are being used by some other application. That's why, you can not delete it. Check whether you can delete those files in safe mode.
Java Byte Verify is a vulnerability, and is itself does not do any harm. Some of the files in Java VM contains "viral" code, but they are not allowed to run or load into memory, and this is detected by AntiViruses as viruses. Microsoft has released a patch for this, you can get it here.
*www.microsoft.com/technet/security/bulletin/MS03-011.mspx
or here...
*www.microsoft.com/security/bulletins/200304_windows.mspx