Unfortunately the fact that Microsoft Security Essentials wrongly detects XP/VS Server as a trojan on Windows XP is a general problem which also applies to other system specific software products.
E.g. Antivir does not show this problem on Windows XP because it correctly detects this.
The only way to solve this problem is to add an exception (allow) after installation of XP/VS Server on Windows XP.
This problem does not apply to Windows Vista, Windows 7 and Server 2008/2008 R2.Tags: Antivir, detected as Virus, Microsoft Security Essentials, Trojan, Windows XP; MSE, XP/VS Server