I have a torjan virus in my lap top and scanned

Download (as in Save, not Run) the installer for a better (and free) antivirus from
 http://files.avast.com/files/beta/5.0.188/setup_av_free.exe
Close the browser and disconnect your laptop from the interned - disable the lan or the wireless. Stop all active Kaspersky protections and uninstall it. Reboot, install Avast and enable the internet connections. Right click on its notifications, select Update, select Engine etc. . After the update is completed right click on that icon again,select to Open the user interface, select Scan Computer, select Boot-time scan, select in Areas to scan the All hard disks option, click Add, click Schedule, click Restart computer. At the end of the scan in the window with the results choose to repair all the system files and delete all the others.
If even this doesn't fix it (or it will not boot again because the infection was too great and your OS was irreparable) all you have left is to reinstall

Try a different antivirus, like AVG or Avira, and they are free. A good place to download programs like this is www.downloads.com.
If u know what trojan is it, there might be a specific remover for it, do u know which one is it?