Bitdefender Realtime Scanner Is Turned On, But It Doesn't Block Any Viruses

Hi!

I am using Windows 2000 Professional (with Service Pack 4) and I installed BitDefender Internet Security 2008 (I bought a BitDefender license for three computers).

But there's still a problem: My BitDefender realtime scanner is turned on but it doesn't block any viruses.

I also have two other computers (one with Windows XP SP2 and on with Windows Vista Home Premium).

On my two other computers it does work perfectly.

I already reinstalled BitDefender but it always results in the same problem.

How do I know that my BitDefender realtime scanner doesn't work?

I always test an Antivirus solution with the EICAR Test-file (http://www.eicar.org/anti_virus_test_file.htm)

on my two other computers BitDefender blocks the Test-file, but on these one it doesn't.

I configured the pc where I have the problem with as a dual-boot (Windows 2000 Pro SP4 - Windows XP Pro SP2).

I installed BitDefender in Windows XP Pro on the same pc and it works but the problem is that my pc doesn't run fast enough under Windows XP and I really would like to use BitDefender on my Windows 2000 installation (but the realtime scanner doesn't work)

PS: Sorry if my English is bad