LUA part 3 (of 5): Compatibility problems

This post is part 3 of a series about using a limited (standard) account in Windows for everyday activities rather than logging in as a computer administrator all the time. (You may want to read part 1 and part 2 before continuing.)

If you follow my advice and switch to a limited account, you may find that some of your programs stop working. This is annoying, but there are various ways to deal with it.

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LUA part 2 (of 5): Setting up separate accounts

In part 1 of this series, I explained why it’s a good idea to have separate accounts on your computer: a standard account for day to day stuff (e.g. reading email), and an administrator account for making system changes (e.g. installing new software).

In this part, I’m going to provide step by step instructions for setting this up on Windows XP. (The process is pretty similar for other versions of Windows.) There are lots of pictures here, to make it as simple as possible. This all applies to a home computer; it’s a bit different for a workplace, since all the accounts will be set up centrally by your IT department, and by default they will just be standard users on each PC.

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LUA part 1 (of 5): Why you shouldn’t always log into Windows as an administrator

The German government have advised people to stop using Internet Explorer and switch to an alternate browser, as reported at the BBC and Mashable. Microsoft have published a security advisory about the problem, and they’ve discussed it on their Security Research & Defense blog. Personally, I’m using IE8 (Protected Mode) on Windows Vista with DEP enabled, so this doesn’t affect me, and switching to a different browser would be an overreaction.

However, this seems like a good time to mention the advantages of “LUA” (Limited User Access). Basically, rather than logging into Windows with full control over the computer, it’s better to have two accounts: one for installing software and one for everyday use. That way, if you run some dodgy code by mistake, you limit how much damage it can do.

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Gantt charts in Excel

I’ve been fiddling around in Excel today, so that I can display a timeline of various activities in a chart. (I think this counts as a Gantt chart, although there are no dependency arrows between the bars like you would see in MS Project.) I got the basic instructions from the help file, but there were a few extra steps that aren’t immediately obvious, so I’m documenting it here for my future reference; hopefully someone else will find it useful too. I’m using Excel 2007; the process will be similar for older versions of Excel, but I don’t know about other spreadsheet applications (e.g. OpenOffice).

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Microsoft exams

Last August, I did a beta exam for Microsoft. I didn’t pay for it, but I didn’t get a score either; the idea was just to test out their new software for doing simulations in the exam (rather than multiple choice questions). As a “thank you”, Microsoft then sent me three vouchers, each one corresponding to a free exam. These expire at the end of June, so I’ve finally had to stop procrastinating and start studying.

Today I did two exams: 70-236 (MCTS: Configuring Exchange Server 2007) and 70-431 (MCTS: SQL Server 2005 – Implementation and Maintenance). According to the booking website, the Exchange exam lasts 4½ hours, and the SQL exam lasts 4 hours, so this looked like quite a long day! Fortunately, I didn’t need all the time that was allocated, so I ended both exams early, and I was at the test centre for about 3 hours altogether.

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Exchange 2007 – firewall problems on Windows 2008

In Windows 2003, the local firewall was turned off by default. You could enable it, but you had to be careful about defining all your exceptions; unlike a PC running Windows XP, you presumably want people to be able to connect to your server! Finding a list of all the relevant ports/protocols could be difficult, and Microsoft sometimes advised people not to enable the firewall at all. SP1 introduced the Security Configuration Wizard (SCW), which helps you to configure the firewall, but you have to specifically install this as an extra component.

In Windows 2008, this changed: the firewall is turned on by default, and the SCW is installed automatically. You can still turn the firewall off, but that’s not ideal from a security point of view: it’s better to configure it so that only certain traffic can get through.

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MazeBot 1

Today, I have mostly been breeding robots…

Back in my undergrad days, I learnt about “genetic algorithms”. The basic idea is that rather than designing a computer program yourself, you allow one to evolve: the equivalent of natural section. I’ve taken advantage of the break between Christmas and New Year to experiment with this; I’m trying to get robots to find their way through a maze. Just to clarify, this is all virtual: I’m writing programs on my computer, rather than building things out of Lego.

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SSL certificate errors

I’ve just been along to the PruHealth website. Unfortunately, it turns out that their SSL certificate expired last night, so I get a big warning message when I try to access the site. I’ve reported the problem to them, and they should be able to fix it fairly easily, i.e. renew the certificate. However, I’ve now seen how different web browsers handle this problem, and I think Internet Explorer does a better job than Firefox overall.

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How to short-circuit a network…

Most modern networks use a star topology: each computer plugs into a separate port on a switch, either directly or via a patch panel, and larger networks will have multiple switches connected together. However, what happens if you plug both ends of a patch cable into the same switch? I’ve encountered this situation a couple of times.

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Downloader-UA.h

There have been a couple of virus warnings in the news today:
Half a million infections of latest Trojan (MSN)
Fake media file snares PC users (BBC)

The basic gist is that there are fake mp3/mpeg files circulating on peer-to-peer filesharing networks. I.e. if you use a program like LimeWire to download a music file or video clip, you may not actually get what you thought. Instead, when you try to play the file, it installs adware on your machine.

I’m sure that I’ll have several people contacting me about this tomorrow, so how bad is it?

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