Experiences here are on an HP Pavilion ze5400 running XP with SP2
I can't accept any liability for your differing results.
They worked for me !

 

ZONE ALARMS problem relating to upgrade to version 6.5.722.000 downloaded from the web.
Basically what happened was that ZA wouldn't start even though zlclient.exe was running in the TaskManager.
The ZA Control Panel was not shown & couldn't be started. It did however flash on screen sporadically.
The System Tray had previously showed the ZA icon - but not any more.
I had tried to reinstall but continually got TrueVector errors connected with .dll files such as SSLEAY.dll, vsmonapi.dll, etc.
I had also tried safe mode, ideas from the forum, etc, and had restored my pc to an earlier stage just before the update, but still to no avail.
Zone Alarms support came up with the following, which I obviously couldn't do due to the inability to see the ZA Control Panel.
- Open ZoneAlarm
- Click Overview -> Preferences (TAB)
- Uncheck "Load at Startup"
Reboot and proceed to install the update.

ZA ( a technical advisor named Bill ) did however also give the actions below WHICH DID WORK - it turned out to be the "fix":
01.) Restart your computer
02.) When you see the screen go black and it starts booting back up keep tapping the "F8" key (at the top of your keyboard)
03.) This should bring up a menu. Choose Safe Mode off the menu by using the arrow keys on the keyboard to highlight Safe Mode and press Enter
04.) If you get a message asking to go to Safe Mode, choose Yes. If you get a help and support window, close this.
05.) Once you are at the desktop, Click Start, My Computer
06.) Click Tools, Folder Options, View Tab
07.) Place a dot next to "Show Hidden Files and Folders"
08.) Remove the check from "Hide Protected Operating System Files (Recommended)"
09.) Choose Yes to the warning
10.) Click OK
11.) Double click C: Note: In the future steps if you do not see any files or folders, please click the "Show Files" link to view them.
12.) Double Click the Program Files Folder
13.) Right Click the Zone Labs Folder, click Delete, and choose Yes
14.) Close this window
15.) Click Start, My Computer
16.) Double Click the C:
17.) Double Click the Windows Folder (It may also be WinNT)
18.) Right Click the Internet Logs Folder, click Delete, and choose Yes
19.) Double Click the System32 Folder
20.) Right Click the Zone Labs Folder, click Delete, and choose Yes
21.) Locate and delete the following files in this folder - imsinstall.dll - imslsp.dll - vsconfig.xml - vsdata.dll - vsdata95.vxd - vsdatant.sys - vsmonapi.dll - vsinit.dll - vspubapi.dll - vsutil.dll - vsregexp.dll - vswmi.dll - vsxml.dll - zlcommdb.dll - zlcomm.dll
22.) Clear your Temp Directory per the instructions below. - Go to Start -> Run - Type %temp% and click OK - Select all of these files and delete them
23.) Clear the Prefetch folder per the instructions below. - Go to Start -> Run - Type Prefetch and click OK - Select all of these files and delete them
24.) Remove the following registry entries by going to Start -> Run and typing in regedit. Use the folders on the left side of the window to navigate to the specified directories.
HKEY_LOCAL_MACHINE\Software\Zone Labs HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\vsmon HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\vsdatant
*Important Advisory: Deleting registry entries incorrectly may cause serious problems to your operating system, which may necessitate the need to reinstall it. Please make sure you are able to perform these deletions correctly before you decide to edit the entries. If you are not sure, you should seek help from someone who is familiar with editing the registry.
For information about how to edit the registry in Windows, from your desktop, click Start >> Run >> and type regedit. Click on Help >> Help Topics.
Under the Contents tab, click Change Keys and Values (this may be found under the How to... section).
Also, you should always make a backup of the registry before editing it. You can find this in the same section of the Help files.
25.) Close this window, then empty your recycle bin.
26.) Restart the computer.
27.) Try to install the latest version again.

HL-DT-ST RW/DVD GCC-4241N CD & DVD Drive stopped working without warning
The drive just stopped working. Most webpages blame the manufacturers for making such an unreliable drive OR a certain games software company for burning it out OR clashing drivers.
Microsoft provide a diagnostics tool named Autofix.exe which can be found at http://www.microsoft.com/downloads/details.aspx?FamilyID=c680a7b6-e8fa-45c4-a171-1b389cfacdad&displaylang=en
You can read about it on the web and then run it. I've located it in Program Files / Program Files / Microsoft Office. It will either hopefully fix it or tell you why it can't fix it.