I am getting the same problem, it keeps giving me an error message "mounting failed" and i tried ti download it for 5 times and its still not working... i have safari version 5.0 and internet connection of 4GB, i am able to download other movies and series except for skype. hope someone can help me

Use the (-) key just to the right of the decimal point, not the - key. The latter is for subtraction.

Please Install Calculator Software Now error
This message means that the operating system has been corrupted. These steps will allow you to update the OS.

Unit to Unit
• Connect two TI-83 Plus units by means of the data cable (short black cable that was prepackaged with the TI-83 Plus)
• Make sure that at least one of the TI-83 Pluses contains the current Operating System
• Select [2nd] Link
• Select "Send OS" option from the Link menu
• Make sure that the other unit still reads "Waiting Please Install"
• The OS should be downloading.

From the Computer
• Make sure you have the latest version of the TI Connect™ Software
• Download the latest version of OS for the TI-83 Plus to the desktop of the PC.
• Connect the appropriate TI-GRAPH LINK™ cable between the PC and TI-83 Plus.
• Since the TI-83 Plus is currently off, the TI-83 Plus will automatically turn on when the TI-GRAPH LINK Cable is inserted.
• On your computer, choose Start, Programs, TI Tools, TI Connect, TI OS Downloader.

type the error code into a websearch, this is a common vista problem, your computer is configured wrong

Hello,
When you change the batteries the display reverts to default setting. My optimistic guess is that the screen display is so light that you cannot see anything on it. This can be arranged.

A Try this before thinking of repairs.

1. Push the ON button.
   
2. Even if you see nothing, press the [2nd] key and release it.
3. Press and HOLD the UpArrow key until the screen darkens.
4. You may have to keep pressing UpArrow for a little while before you see anything.

B If that does not work

1. Remove one of the AAA batteries.
   
2. Press and hold the [CLEAR] key.
   
3. Whileholding [CLEAR], reinsert the AAA battery and then
   
4. turn the calculatoron.
   
5. The calculator should display the message "RAM Cleared".
   
6. Release the [CLEAR] key and then press it one more time to remove the message "RAM Cleared".

C. Third option

1. Remove batteries including the backup battery for 5minutes.
   
2. After the 5 minute period, reinsert all of the batteries and
   
3. turn the calculator on.
   
4. Adjust the contrast if necessary.

D. Last option

The last option requires the reinstallation of the system. So to use it you must download the TIConnect 1.6 software from education.ti.com. You must have the TI USB SilverLink or the TI Black serial cables ready.You must be connected to the Internet.

1. Remove one of the AAA batteries.
   
2. Press and hold the [DEL] key.
   
3. Whileholding [DEL], reinsert the AAA battery and then
   
4. turn the calculatoron.
   
5. The calculator should display "Waiting...Please install calculator software now".
6. Connect the TI Connectivity cable between the computer and the calculator.
7. Click on Start >> Programs >> TI Tools >> TI Connect >> TI OSDownloader.
8. Follow the on-screen directions to reinstall the calculator's OS.

If the message "Error! Press any key to turn unit off. Then turn unit backon." appears on the graphing calculator, quickly, remove one battery from the calculator and reinstall it while the transfer is taking place.

If all else fails you can contact Texas Instruments at [email protected]

Hope it helps.
Thank you for using FixYa.

Hello,
When you change the batteries the display reverts to default setting. My optimistic guess is that the screen display is so light that you cannot see anything on it. This can be arranged.

A Try this before thinking of repairs.

1. Push the ON button.
   
2. Even if you see nothing, press the [2nd] key and release it.
3. Press and HOLD the UpArrow key until the screen darkens.
4. You may have to keep pressing UpArrow for a little while before you see anything.

B If that does not work

1. Remove one of the AAA batteries.
   
2. Press and hold the [CLEAR] key.
   
3. Whileholding [CLEAR], reinsert the AAA battery and then
   
4. turn the calculatoron.
   
5. The calculator should display the message "RAM Cleared".
   
6. Release the [CLEAR] key and then press it one more time to remove the message "RAM Cleared".

C. Third option

1. Remove batteries including the backup battery for 5minutes.
   
2. After the 5 minute period, reinsert all of the batteries and
   
3. turn the calculator on.
   
4. Adjust the contrast if necessary.

D. Last option

The last option requires the reinstallation of the system. So to use it you must download the TIConnect 1.6 software from education.ti.com. You must have the TI USB SilverLink or the TI Black serial cables ready.You must be connected to the Internet.

1. Remove one of the AAA batteries.
   
2. Press and hold the [DEL] key.
   
3. Whileholding [DEL], reinsert the AAA battery and then
   
4. turn the calculatoron.
   
5. The calculator should display "Waiting...Please install calculator software now".
6. Connect the TI Connectivity cable between the computer and the calculator.
7. Click on Start >> Programs >> TI Tools >> TI Connect >> TI OSDownloader.
8. Follow the on-screen directions to reinstall the calculator's OS.

If the message "Error! Press any key to turn unit off. Then turn unit backon." appears on the graphing calculator, quickly, remove one batteryfrom the calculator and reinstall it while the transfer is taking place.

If all else fails you can contact Texas Instruments at [email protected]

Hope it helps.
Thank you for using FixYa.

Hello,
When you change the batteries the display reverts to default setting. My optimistic guess is that the screen display is so light that you cannot see anything on it. This can be arranged.

A Try this before thinking of repairs.

1. Push the ON button.
   
2. Even if you see nothing, press the [2nd] key and release it.
3. Press and HOLD the UpArrow key until the screen darkens.
4. You may have to keep pressing UpArrow for a little while before you see anything.

B If that does not work

1. Remove one of the AAA batteries.
   
2. Press and hold the [CLEAR] key.
   
3. Whileholding [CLEAR], reinsert the AAA battery and then
   
4. turn the calculatoron.
   
5. The calculator should display the message "RAM Cleared".
   
6. Release the [CLEAR] key and then press it one more time to remove the message "RAM Cleared".

C. Third option

1. Remove batteries including the backup battery for 5minutes.
   
2. After the 5 minute period, reinsert all of the batteries and
   
3. turn the calculator on.
   
4. Adjust the contrast if necessary.

D. Last option

The last option requires the reinstallation of the system. So to use it you must download the TIConnect 1.6 software from education.ti.com. You must have the TI USB SilverLink or the TI Black serial cables ready.You must be connected to the Internet.

1. Remove one of the AAA batteries.
   
2. Press and hold the [DEL] key.
   
3. Whileholding [DEL], reinsert the AAA battery and then
   
4. turn the calculatoron.
   
5. The calculator should display "Waiting...Please install calculator software now".
6. Connect the TI Connectivity cable between the computer and the calculator.
7. Click on Start >> Programs >> TI Tools >> TI Connect >> TI OSDownloader.
8. Follow the on-screen directions to reinstall the calculator's OS.

Ifthe message "Error! Press any key to turn unit off. Then turn unit backon." appears on the graphing calculator, quickly, remove one batteryfrom the calculator and reinstall it while the transfer is taking place.

If all else fails you can contact Texas Instruments at [email protected]

Hope it helps.
Thank you for using FixYa.

Hello,
Read the following from the TI knowledge Base. Hope it helps

Reinstalling the OS fot the TI84Plus

How do I correct the Error Waiting...Please Install Calculator SoftwareNow message on my TI-83 Plus family or TI-84 Plus family calculator?

If an operating system (OS) update fails or is interrupted, the calculator will be in an inoperable state with the message Waiting...Please install calculator software now.The most common cause of a transfer being interrupted is updating the operating system on a calculator with low batteries. Users will need to use the TI Connectivity cable and the TI Connect to send the operating system to the calculator. Make sure to have the latest version of TI Connect installed on the computer.
In order to install the software please follow these steps:
1. Connect the TI Connectivity cable between the computer and the calculator.
2. Click on Start >> Programs >> TI Tools >> TI Connect >> TI OSDownloader
3. Follow the on-screen directions to reinstall the calculator's OS.
If the message "Error! Press any key to turn unit off. Then turn unit back on." appears on the graphing calculator, quickly, remove one battery from the calculator and reinstall it while the transfer is taking place.

Try and resolve this issue by re-installing the calculator's operating system using the TI OS Downloader. To do this, please follow the steps listed below. Be sure you have fresh batteries in your calculator.

1. Download the OS 2.43 file to your computer (preferably the desktop).

2. Open the TI OS Downloader by going to Start>>Programs>>TI Tools>>TI Connect>>TI OS Downloader. If you do not see TI OS Downloader, you may need to install the latest version of TI Connect. You can download a free copy from:
www.education.ti.com/downloadticonnect

3. From the main screen, select your calculator and cable type. Click "Next" to continue.

4. From this screen, locate the OS 2.43 file by clicking on the yellow browse folder and navigating to the location where you downloaded it. Double-click the OS 2.43 file to select it.

5. Remove one triple A battery from your TI-84 Plus. With the battery removed, press and hold the [DEL] key while you re-insert the battery.

6. You should see a "Waiting..." message on the screen of your calculator. If so, disconnect the USB cable from your computer, re-connect it and then click "Start Download". This should begin the OS transfer process.

First of all: the usb cable without the bulky thing is the right cable.

For the os problem: you have to re-install an OS on your calculator.

1. Download the current OS. You can download version 2.41 here: http://education.ti.com/educationportal/appsdelivery/download/download.jsp

2. Install the ti connect software if you haven't.
3. Connect your calculator to your pc.
4. Go to the folder you installed ti connect in and start TIOS Downloader.
5. Follow the instructions. It will ask for the calculator type, cable type (just choose USB Cable) and will ask where to find the OS. Follow the last instructions and press start download.

If this doesn't work, please let me know

Gr Marijn

Try holding [left][right][2nd][on], that reinitializes the calculator and clears the ram. If that doesn't work you could try reinstalling the OS (refer to manual for details). If it still doesn't work, you will probably have to call TI.