According to this page then iosdt.exe is a trojan horse (To get rid of it update your antivirus, or use an utility like TrojanHunter)
[Oct 2003] A trojan claiming to be a “Product Activation” tool is in circulation. It installs in %windir%/system32/iosdt/. The id is firstname.lastname@example.org. It emails it’s log files through smtp.o2.pl. You will see a process, iosdt.exe, using taskman.