I called up Rockstar's support, and actually spoke to a person within 2 minutes of calling. I told him my problem and he said it is a commonly found problem. he sent me an email detailing methods to fix it. A copy / paste of the email...:
I've done everything listed except #5, which says to update the firmware. My DVD drive is from Ibuypower.com (I've had it for two years), and has no manufacturer listed anywhere on the drive. I called up Ibuypower, and they said it could be one of a multiple of brands. Without the brand, the firmware cannot be updated.Dear Sir/Madam
Thank you for contacting Rockstar Technical Support.
Below are some general troubleshooting steps for bypassing the 'unable to
authenticate' error message. Try the game after each of these steps
1.) If at all possible, try installing and running the game from another
drive on the PC
2.) click Start, then Run, then type MSCONFIG and click OK. From there
click on the tab marked startup.
For Windows XP users click the button marked as Disable All, then click
Apply and Close.
For Non Windows XP users, please remove the ticks from all of the boxes
apart from the below four and then click Apply and close.
LoadPowerProfile
ScanRegistry
SystemTray
TaskMonitor
Once this has been done, please reboot the computer and then try the game
again.
3.) Empty the contents of the temp folder. Click start then choose run.
Type "%temp%" without the quotes. Press Ctrl and A to highlight all of the
files in this folder and press delete. These files are not needed past
their initial use within windows.
4.) Check the bottom (silver) side of the CD for any marks, scratches,
smudges, fingerprints or dust particles. If any are found, take a soft damp
cloth and wipe the bottom side of the CD starting from the inside and
working to the outside. You also may want to see if you can get an exchange
for your cd to see if you may just have a defective cd. It would be faster
if you went that route first.
5.) We have found that in most cases that the current dvd rom drive does
not have updated firmware. Updated firmware is required because most copy
protected cd's are updated. Old firmware will not regonize new copy
protection. You should contact the PC manufacturer or visit the DVD drive
manufacturer's website for any firmware updates
6.) In certain cases, CD writing and disc emulation software can interfere
with reading the protection on a disc. Disable any virtual drives related
to CD writing and disc emulation software (consult the help file for these
programs for instructions onhow to do so). As a last resort it would also
be beneficial to remove this software from the system entirely
7.) Changing the compatibility mode may also help to run the game. Locate
the GTA SA.exe file or the desktop shortcut for the installed game.
Right click on the San Andreas icon and select properties. Click the
compatibility tab and tick the box labelled 'run this game in compatibility
mode for:' Try each of the options being sure to press OK to confirm the
changes after each one
5.) If the system has Sonic DLA installed then it may also interfere with
running the game. Go to start then run and type "cmd" (without the
quotes) At the command prompt type dla disable X: where X is your dvd
drive letter.
Please be sure to delete all previous correspondence when replying. This
will help us to process your response in a more timely and efficient manner.
Kind Regards,
Rockstar Technical Support
However, the people at Ibuypower said it's probably not a firmware problem anyway. If any of you think otherwise, let me know.
I called up Rockstar support again, and was again speaking to a real, living person within two minutes. I told them I had exhausted all the methods listed in the email with no success. They told me they are elevating the problem to the head office and I will receive an email. I have yet to receive that email.
My thoughts are that either I have to update my firmware (which I cannot do without knowing the DVD ROM's brand), or I have to get a new DVD drive. I would rather not spend any money.
I'm open for suggestions / solutions.
