I have a problem

[jef71]

hello, since I charged your antivirus avast 4 family edition when the antivirus detects a virus that starts again my PC without my opinion it is necessary to make a special adjustment??? configuration:windows XP

[Lisandro]

Strange, avast scanning shouldn't reboot the system... maybe you're infected.
It will be good if you can:

1) Disable System Restore on Windows XP: http://support.microsoft.com/default.aspx?scid=kb;%5BLN%5D;310405
2) Clean your temporary files.
3) Schedule a boot time scanning with avast. Start avast! > Right click the skin > Schedule a boot-time scanning. Select for scanning archives. Boot.
4) Use a-squared, ewido or Spyware Terminator (trojan removers).