Expert
computing advice (Part 1)
Invalid
com errors
My 18-month-old Windows 7 laptop
grinds to a halt every time I try to use it. Finding and fixing any registry
errors and hard-drive corruption using lob system mechanic solves the problem
until the next restart. I’ve uninstalled the progRAMs I don’t use and clear the
cache twice a day. I don’t know what to do next. Many of the faults reported by
lolo concern invalid COM references (see screenshot, right).
It’s difficult to diagnose this issue
without further information, but the fact that a clean-up utility is able to
alleviate the problem suggests that it isn’t the laptop’s hardware at fault. If
the issue is recurring regularly, it’s possible that you’re running low on
hard-drive space.
The Windows registry contains hundreds
of thousands of entries, which makes the 20 or so errors reported by system
mechanic a drop in the ocean and somewhat irrelevant. Check your remaining disk
space next time the problem occurs. You’ve already uninstalled the applications
you don’t need, but some additional spring cleaning may be required to tree up
enough space for Windows to store the temporary files it creates during normal
operation. Keep at least 15 percent of your drive’s capacity free.
Autorun worm
For several years I’ve been using a
portable hard drive to store valuable data, but I recently picked up what I
believe to be a malware infection. Microsoft word documents now feature the
file extension .exe rather than .doc, while other tiles and directories have
been converted to link files. Please help me reclaim my tiles.
This looks like the work of an autorun
worm. Such malware is designed to infect shared files on a network, or those
stored on removable devices such as your USB drive.
An up-to-date antivirus should be able
to detect and remove this worm. Launch your security progRAM, install any
updates, then set it to perform a full system scan.
Autorun worms use Microsoft word files
as a vehicle on which to propagate themselves, rather than destroying the
information stored within. By changing the file extension to .exe, innocent
users wanting to open the word document are tricked into launching the
malicious code attached.
Because the worm doesn’t tamper with
the data stored within the word document. Your antivirus software should be
able to clean the infected files and return them to their original state for
editing.
McAfee’s ant virus has reportedly
recovered tiles damaged in this way; many other progRAMs will also be up to the
job.
Sketching software
I’m struggling to find some interior
design software for cafés and restaurants for use on my Windows 7 PC. Are you
able to recommend some user-friendly software?
Google SketchUp (sketcbup.qoocjle.com)
is a free application that’s useful for all sorts of 3D design. It’s very
powerful, but designed with ease of use in mind; plenty of online tutorials can
help you get started.
If you need more functionality,
upgrade to SketchUp Pro. This adds professional features and a 2D layout
module.
For more simple tasks, such as
creating quick floor plans. You can try a site such as floorplanner.com. This
runs within your browser; so you don’t need to download and install additional
software. As with Google Sketchup, the basic version is free. More advanced
options can be added on a sliding price scale.
Two networks, one router
I live above my small business and use
six Windows 7 and XP PCs for work and leisure. These are currently linked to a
single router and Wi-Fi network. I’d like to separate my home and business
networks. But control both from a master PC running Windows 7. Please tell me
how to proceed.
There are a number of ways you could
achieve this, Ian. The most elegant solution would be to use a router that
supports virtual LANs (VLANs). This feature allows a single router to maintain
a number of separate networks internally and assign them to different external
ports.
Using such a router, you can set up
two networks as if you were using two routers. The PCs connected to one network
won’t be able to see those configured to access the other. You can also set u
wireless clients to attach to the VLANs.
Because the VLANs are managed by the
same router, your master PC will see and can be assigned to both
simultaneously.
Another approach is to install a
second network adaptor in your master PC (some models have two network ports as
standard, in which case this isn’t necessary). This solution is more
complicated, however, as you would then need to configure each network as a
different subnet and set up routing within Windows on the master PC. And if
you’re using a DHCP server to assign IP addresses, you would need to ensure
that this also has access to both subnets.
If your current wireless router doesn’t
support VLANs, you may need to invest in a new model. Take a look at Cisco’s
$190.4 RV120W (pictured below) and Netgear’s $302.4 ProSecure UTM5.
