4 copies of svchost.exe is not necessary bad. Before worry about mailware or virus, do a search for svchost.exe on your PC. The valid locations that may have svchost.exe are:

C:\Windows\System32
C:\Windows\ServicePackFiles\i386
C:\Windows\$NtServicePackUninstall$
C:\I386

If you find a copy somewhere else, then go ahead to scan your hard drive for virus or other stuff.

看得頭昏腦脹，各位大大解說得很詳細，我卻是有看沒有懂，唯一記住的是--->只要在windows\system32\以外的地方找到Svchost.exe文件，那麽可以說就被病毒感染了。
因為這個比較好記又好用！

As my previous post (#11) indicated, svchost.exe can be found at locations other then \windows\systems for reasons. While it is a good idea to always check for virus but finding svchost.exe besides \windows\system32 should not be the reason.

沒有問題！我也有四個！！！

many thx,

Now I know what is this.