There are two problems with my computer. First, occasionally when inserting a disc into the CD/DVD drive a message appears saying “E drive is inaccessible”. Second, after a while on the internet a message appears for the wireless adapter saying “Limited or no connectivity” even though the signal strength is strong. The problem only seems to occur when no one is actively using the internet for a period of time and can be fixed by restarting the computer. The computer is running Windows XP and has a Netgear WPN111 wireless adapter.

Dealing with your first question about the CD/DVD drive being inaccessible I assume that the full error message you are receiving is “E drive is inaccessible – incorrect function” as I have not seen the “drive is inaccessible” message by itself without the “incorrect function” message as well. In any case, working on the assumption that you are receiving this message the most common cause is related to the CD burning capabilities of Windows XP. Newer versions of Windows, including Windows XP and Windows Vista, have the built-in ability to write CDs without the need to use an external program. However, there are certain situations in which Windows XP does not agree with the type of disc you have inserted into the drive and throws the “incorrect function” message. The most common situation is when you insert a blank CD or DVD into the drive (or a writable CD or DVD which has previously had data written to the disc) and then attempt to open the disc using My Computer or Windows Explorer. In this situation, if the CD burning capability has not been enabled on the CD drive it will be unable to process the inserted disc and return the relatively uninformative “incorrect function” message and deny you access to the drive. As a starting point, we need to ensure that CD burning is enabled on the drive. Open My Computer or Windows Explorer and right-click on the CD drive and then select “Properties”. In the window that appears click the “Recording” tab. Ensure that “Enable CD recording on this drive” is enabled. Click OK to save and close. Now check whether you are able to open and access the CDs which were previously inaccessible.

Should the problem continue, if you have any third-party CD burning software (e.g. Roxio, Nero, etc.) on the computer try uninstalling that software to see whether the problem continues. It is quite possible that third-party software may conflict with the built-in Windows XP CD burning capabilities.

If the error message still appears you should next remove the UpperFilters and LowerFilters values for the CD/DVD drive. These values are located in the Windows Registry (the central repository for all important Windows settings on your computer) and, from what I understand, they specify the device-specific drivers for your CD/DVD drive. By removing these entries we are forcing Windows to re-create these entries and ensure the correct drivers are assigned against your drive. As you can see, this helps ensure that the correct drivers are being used. Be aware, modifying the Windows registry is a risky process and could result in serious damage to your installation of Windows if not done correctly. As such, I strongly suggest that you only proceed with these changes if you are confident. Assuming that you would like to proceed go to the “Start” menu > “Run” and type “regedit” (without the quotes) and click OK. The Windows Registry Editor will appear. Navigate to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}. Make sure that you are at the correct key, as quite a few of the keys have similar names. Once you have arrived at this registry key in the right-hand pane you should see two registry entries: “UpperFilters” and “LowerFilters”. Right-click on each of these entries and click “Delete”. If you see UpperFilters.bak or LowerFilters.bak entries do not delete these entries, as they are different. Be aware, you may only see a LowerFilters entries. In this situation just delete the LowerFilters entry. Once this has been done, restart the computer and check whether the problem persists. However, if you do not see a LowerFilters entry, or the problem still persists after deleting the entries, visit the following Microsoft Knowledge Base article for further guidance: support.microsoft.com/kb/314060 .

Moving onto your second question, the “Limited or no connectivity” message over wireless generally means that while there is still a strong signal, data is not able to properly transmit over the medium. Doing some research there are quite a few other people who have commented that the Netgear WPN111 adapter can be temperamental and that they have also experienced this problem. However, short of replacing the WPN111, there is no way to know for certain whether the problem is the adapter since there are many other points of failure. As a first step you should visit the Netgear website and download the latest drivers for the WPN111 adapter and then install these drivers on the computer.

If after downloading and installing the latest drivers the problem continues, you could try changing the method by which your wireless adapter is managed within Windows. Netgear wireless adapters come with their own wireless management utility but you can also use the in-built Windows wireless utility. Depending on which method you are currently using try switching to the other method to see whether you obtain a more stable connection. You should be able to switch between the two utilities by editing the configuration in the Netgear utility to either use that utility or the Windows utility.

Should you continue to have problems with the wireless there are some more comprehensive steps we can attempt which are beyond the space remaining in this column, in which case please contact me again.