I havean acer aspire one mini-netbook that crashed a few days ago. I don't think I need a new hhardrive but I knoe for sure that I need to re-install the OS but I don't know how to. I also don't have a cd drive..can anybody help?

Hi, You must have CD installation to reinstall the OS. Turn on your laptop, connect external CD/DVD ROM to USB. Insert the OS CD then follow the steps on your screen to complete the process. You will prompted to repair the OS during process , follow the instructions to repair OS.

The Acer Aspire One netbook version with Windows XP has a partition on its hard disk drive that is normally hidden that contains the complete installation images for the Operating System, Applications and Drivers. If Windows XP is no longer accessible, restoration can be done using an Alt-F10 to access. The following procedure is edited of the AcerSystem User Guide and is as follows.
The computer is restored to its original factory settings without recovery CDs.
This recovery process helps you restore the C: drive with the original software content that is installed when you purchase your notebook. Follow the steps below to rebuild your C: drive. (Your C: drive will be reformatted and all data will be erased.) If possible, back up all data files before using this option.
Before performing a restore operation, please check the BIOS settings by activating the BIOS utility - press during the Power On Self Test.
1 Check to see if Acer disk-to-disk recovery is enabled or not.
2 Make sure the D2D Recovery setting in Main is Enabled.
3 Exit the BIOS utility and save changes. The system will reboot.
To start the recovery process:
1 Restart the system.
2 While the Acer logo is showing, press at the same time to enter the recovery process.
3 Refer to the onscreen instructions to perform system recovery.