I dropped the laptop now at start up there is a disk error

It may be bad. Has the laptop been damaged? Dropped? Open Device Manager, DVD/CD Rom drives, is it listed? In Start Menu, Computer, Is it listed? Try re installing the DVD rom driver, the MS Vista 32bit drivers can be found here: http://www.dell.com/support/drivers/us/en/04/Product/vostro-a860

Click start control panel administrative tools computer management then select event viewer this may vary depending on what operating system you have extend the events there you will see errors in red you will no what exactly what the error was and at what time it occured Right click on the error message select properties you will see all details about the error or click start type in event viewer press ENTER you might be able work your way through the problem

Hard drives do not like being dropped even inside a notebook. It is a sure way of destroying a hard disk.
First - re-seat the harddisk and reboot the computer. If the computer does not boot up then reboot andgo into the BIOS configuration to see if the BIOS detects the hard drive. If itdoesn't detect the hard drive then it could be faulty.
Then the hard drive needsto be replaced in the computer/laptop, Windows installed and the computer orlaptop's device drivers plus your programs etc. to get a functioningcomputer/laptop again.

Seems that your notebook's hard drive was physically damaged due to the shock it got after your notebook fell. Try a replacement hard disk.

The error PXE-E61: Media test failure usually means the hard diskhas failed or the hard disk needs re-seating or the disk controller is faulty.First - re-seat the harddisk and reboot the computer. If the computer does not boot up then reboot andgo into the BIOS configuration to see if the BIOS detects the hard drive. If itdoesn't detect the hard drive then it could be faulty.Then the hard drive needsto be replaced in the computer/laptop, Windows installed and the computer orlaptop's device drivers plus your programs etc. to get a functioningcomputer/laptop again.

No bootable device suggests that your Acer Aspire hard disk may have been damaged when the computer was dropped.
You should try opening the cover on the base of the laptop where the hard drive is fitted and check to make sure that the drive is seated firmly and has not come loose with the drop. See the Acer Aspire 5253 Quick Start Guide for the location of the drive cover.
If reseating the drive does not help, then you would need to find any recovery discs that you may have made or received with the laptop plus need to buy and install a replacement hard drive.

sounds like bad luck. your hard disk or the cable to your hard disk is gone.
try to take it to a service center.

I dropped my Dell Insiron too. It seems to have had the same result as your's. I had to get a new motherboard (system board), before it would work again.

If you have dropped the laptop while it was switched on and running, there is a high likelyhood that you have damaged the hard drive.
This error message means it could not find the hard disk (and therefore cannot find the operating system) it means the fault could be a faulty hard disk controller or a faulty hard disk.
Try reseating the hard disk and if this doesn't work, go into the BIOS configuration and see if the hard disk is detected, if not most likely the hard disk has failed.
You need to replace the faulty hard drive, install Windows, the device drivers and programs to get the laptop working again.
All the data on the hard disk is lost.
Sorry to be the bearer of the bad news, you will have to tell her.