Problems with home edition and Vista

Hallo there?

There are 2 problems with avast home 4.8 on my computer.

First one

When i start up the program, the memory scan starts ----> if i dont stop the scan the program will crash

Second one

When i do a full system scan (deep scanning) the program finds a trojan horse and gives me several solutions to solve the problem (remove to trashbin, or remove from computer – this is perfect) but when i accept the order to delete from computer or put it in jail program crashes. it just shuts down.

I did try to start with a full scan when computer starts up but this has no effect on this issues

Is there a solution for this problem, Is this a known problem? if it is where can i find the solution.
On my previous computer with windows Xp it worked fine…

Thx for reading
and i hope you people can help me out.

Did you have any other antivirus before avast? Which one? How did you remove it?

About the second, can you say what is the infected file name, where was it found (C:\windows\system32\infected-file-name.xxx)?
What avast! version and virus database are you using? (see About dialog of avast!)