Ricsi-831 and Win32:Patched-HO [Trj]

Hello,

avast detected these two infections on my System (windows 7):

Ricsi-831 in the file hiberfil.sys and
Win32:Patched-Ho [Trj] in the file pagefile.sys.

Unfortunately I don’t know in which file the origin of these two problems is. I Suppose in one of the thousand .zip or .cab files :(.

And this induced my next question. Is there a realistic (and fast) possibility to remove that infections without setting up a new system?

If I’am forced to set up a new system, can I do this with the recovery-partition on the infected computer? (Stupidly i forgot to create the rescue disc)