MC75A after reboots shows the appcenter but freezes the screen not able to click on anything.

If you have Windows
Left-click START or the round blue Windows icon at bottom left of screen.
Or press the Windows key at bottom row of keyboard.
Left-click the white right-arrow symbol next to "Shut down".
This drops down a choice menu.
Left-click "Restart".
Now sit back and watch the magic happen.

Otherwise to shut down click the Shut down bar in Start window.

Or in case the PC freezes / hangs press "Power" button.

If an application hangs, stopping your computer, you can also try close down the app in "Task Manager".
Press Ctrl+Alt+Del
Wait until the Task Manager options window pops up on screen.
Left-click "Start task Manager"
Left-click "Applications"
Shut down the app then exit TM.
Reboot to refresh memory.

Press the #1 and #9 while turning on the device.

keypad not work

try uninstalling a few unnecessary programs then click start run type cmd then type chkdsk/r/f this should schedule to happen on reboot which will scan for and attempt to recover bad sectors and automatically fix any corrupt files on your hard drive or
click startcontrol panel administrive tools,computer management ,disk management right click on your drive select properties click tools you should see click check now click start two boxes automatically fix files and scan for and attempt recovery of bad sectors place then a tick in both boxes then select check now,start should schedule this task when restart
do not do anything while the chkdsk utility is in progress any input may damage your computer
then you should test or replace all leads make sure they are securely seated and are not bad/faulty that are attached to your (((motherboard to your hard drive)))
do not do anything while the chkdsk utility is in progress any input may damage your computer
then click start all programs accessories system tools defragment your hard drive

you might have to install more RAM random access memory to check how much ram you have click start right click on my computer select properties you will see all imformation about your computer including installed ram

scroll to the bottom toolbar (bottom of screen) right click you can select task manager applications also processes you will see whats running on your computer you might have virus slowing your computer also select users you will see who is using your computer
hope this helps
don

During the boot process you will see on the screen to press a certain key to enter setup
Press and hold that key during the boot up process to enter BIOS you can load failsafe defaults or load optimized defaults ,press escape then press f10 to save to cmos to restart
once you have your computer running
try uninstalling a few unnecessary programs then click start run type cmd then type chkdsk/r/f this should schedule to happen on reboot which will scan for and attempt to recover bad sectors and automatically fix any corrupt files on your hard drive or
click startcontrol panel administrive tools,computer management ,disk management right click on your drive select properties click tools you should see click check now click start two boxes automatically fix files and scan for and attempt recovery of bad sectors place then a tick in both boxes then select check now,start should schedule this task when restart
do not do anything while the chkdsk utility is in progress any input will damage your computer
then you should test or replace all leads make sure they are securely seated and are not bad/faulty that are attached to your (((motherboard to your hard drive))
defragment your hard drive will speed up your computer
scroll to the bottom toolbar (bottom of screen) right click you can select task manager applications also processes you will see whats running on your computer you might have virus slowing your computer also select users you will see who is using your computer
don

Click on Start
Click on RUN
Type MSCONFIG
from the window Click on STARTUP tab
UnCheck all the programs related to Adobe,Java,Yahoo, MSN etc and Any update related programs,
Click Apply or OK, Restart the PC

Once you restart You will get a window of System Configuration. Click on Do not show me this window again.

Incase you find anything missing or going wrong after rebooting. Open MSCONFIG and put check on the application in STartup tab

Start by logging on as the Administrator so you can check the Task Manager and find out what Application or Process is monopolizing the system.

If the system is still unresponsive boot into Safe Mode. (Press F8 before the Windows startup screen appears.) If everything is fine in Safe Mode type MSCONFIG at the Command Prompt and start disabling features until you find the culprit.

Last resort, buy or borrow an external USB CD/DVD drive and use it to reinstall Windows.

Important: Reinstalling will ERASE the hard drive.

If this helps please vote for my solution.

I had this problem and I've tried everything posted and nothing worked so I just started messing around with my phone and may have figured it out. Here's what I did.
NOTE: I AM NOT RESPOSIBLE FOR ANYTHING THAT HAPPENS AND YOU ARE SOLEY DOING THIS ON YOUR OWN AT YOUR OWN RESPOSIBLITY. Good Luck

1. Click the Menu Button
2. Scroll to Options Icon (the wrench) and click it
3. Click Advanced Options
4. Click Applications and wait for the Apps to load.
5. Scroll down and delete the apps that you dont need (see what I deleted)
6. I first deleted ICQ Messanger by scrolling over it and selecting the menu button then clicked delete, then clicked Yes and let it reboot
7. After it rebooted I clicked the Camera button on the side and it worked after I rebooted
8. Then I went back in and deleted Yahoo Messanger and let it reboot again. (This is up to you)
9. Last I deleted Windows Live Messenger and let reboot once again. (This is up to you)
I deleted these because I didnt use them anways. These were the only 3 apps that I deleted since I never used them. If you want, you could even delete Brick Breaker if you dont play it but I wouldnt delete any other Apps other than these.

Try resetting the PRAM by turning on the iBook then holding option + command + P + R and wait till u hear another chime. If it still freezes, it may indicate an application may be causing it to lock up hold shift after you hear the chime to boot OS X into safe boot.

you got virus, and Trojan on your laptop.
need to go buy a good antivirus software. i.e. symantec, McAfee, etc..........
ask the sales person in the store.
scan the laptop.