No blocks downloaded - MS Security Essentials users please read

I got my friend to download and try Bitcoin out. I sent him one coin, but he hasn’t received it. For some reason, his client isn’t downloading any blocks. He turned on “Generate Coins” the minute he started the program for the first time. His speeds were in the 1400-1600 khash/s range, and he had 3 blocks. He generated 50 coins which will mature in another 100 blocks or so. He has around 40 connections.

To my knowledge, his coins will be invalid because none of the other nodes will accept his blocks. And, since he hasn’t downloaded any blocks, he won’t receive the one Bitcoin I sent him.

He uses Microsoft Security Essentials, but has added Bitcoin to its unblock list. He does have port 8333 open, but has a Linux network firewall. (He doesn’t have the rights to access the firewall.)

What could be the problem?

Maybe, the hdd is full?

Yea, possibly a full disk, or a failing disk… It’s odd that even with a dedicated connection within your LAN it took that long to get that number of blocks. My 100 Mbps router funneled them from one of my PCs to another in less than 15 minutes, at the 65K+ blocks it needed.

Maybe a flakey router or internet connection? Might be worthwhile to do a speed test, or research Microsoft Security Essentials to make sure it’s not toying with Bitcoin’s ability to build the block list in some other way… not too familiar with Microsoft products I’m afraid. 😐

Okay, I solved the problem. The solution was in topic 35

So that was responsible for keeping blocks from downloading?

The link: “Win32 CPU Cycles vs ‘Live Protection’ Engines”

For BitcoinFX, Live Protection was keeping it from getting CPU for generating coins.  You said your friend was getting 1400-1600 khash/s, so it was getting CPU.  I guess Live Protection must have been blocking some other part of the program then?

Well, I asked him to add bitcoin.exe to the “Excluded processes” list of Microsoft Security Essentials, and block downloads took off for him after that.

Here is a guide on how to exclude a process:

http://maximumpcguides.com/windows-7/set-microsoft-security-essentials-to-exclude-a-process/

You need to exclude bitcoin.exe from live protection.

Okay, I solved the problem. The solution was in http://bitcointalk.org/index.php?topic=35.0.

This worked for me too! Thanks. 😄 Microsoft Security Essentials was locking up the bitcoin.exe process. The thread with the solution has several responses from other people running various editions of Windows. The problem may extend to other virus protection software. You just have to exclude the bitcoin.exe process from its scan, and it’s probably healthy to add the block database files to the exclude list as well. Of course, this opens the excluded files up to infection, but it’s a risk you’ll have to take until another solution can be found. 😉