Error 42100?

Avast Free Antivirus / Premium Security
1

Hi,

I scheduled a boot time scan of my system. While the scan starts, nearly every single file being scanned reports:

Error 42100

Can someone please tell me what’s wrong?

Thanks,

tigemac

2

Search the board for 42100

For instance: http://forum.avast.com/index.php?board=2;action=display;threadid=7385;start=msg65693#msg65693

FAQ on my signature contains a list of avast errors (page 4) 8)

3

Yep…makes sense since I have an AMD64 FX-53 CPU.

However, does this mean that Avast! does not work AT ALL? Or just at boot time scan???

When is the scheduled fix due?

Thanks!

P.S. I searched for 42100 before posting, but oddly enough (and as another user pointed out) I did not get any hits. Thus the redundant post (sorry).

4

I’m afraid you’re right. Unless you (temporarily) remove the /noexecute flag from boot.ini, avast does not scan correctly for viruses (won’t even detect the EICAR test file).

Another work around is to update to the 4.5 beta (see the other section of this forum for instructions for how to do ths).

Thanks
Vlk

5

Please clarify your response for me. Am I correct about #1 or #2 when using an AMD 64bit processor with the current version of Avast!?

  1. Avast does not scan for viruses properly AT ALL (meaning Avast will not detect viruses during a boot time scan NOR will it properly detect viruses when doing a scan from within Windows???).

-OR-

  1. Avast DOES properly scan for viruses in Windows, but just does not work at boot time without the boot.ini modification?

In addition:

Q. I assume that the boot.ini file which needs be modified is the one in the root of C:? Here is mine:

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS=“Microsoft Windows XP Professional” /fastdetect /NoExecute=OptIn

I assume you mean just remove the entirety of “/NoExecute=OptIn” as above while leaving the rest intact?

What function does the “/NoExecute=OptIn” provide? Was this line added my Avast originally?

Thank you.

6

BumP!

Can someone please tell me?

Thanks!! ;D

7

It is more or less #1 but not entirely. In short: avast does detect some viruses but a large quantity of them doesn’t. Namely, only simple (string-defined) viruses are being caught.

I assume you mean just remove the entirety of "/NoExecute=OptIn" as above while leaving the rest intact?

Yes.

What function does the "/NoExecute=OptIn" provide? Was this line added my Avast originally?

No, this line was added by the XP SP2 installer. The NoExecute switch turns on/off the new Data Execution Prevention (DEP) Feature of XP SP2. http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/sp2mempr.mspx

DEP is a very good feature but as already said, is currently NOT compatible with avast.

A fix will be included in avast 4.5 which is due Saturday, November 13th.

Hope this helps,
Vlk

8

Helps very much! Thank you sir!