Lenovo SL 500 not booting after startup only black screen with cursor is seen

Hi.
I would say your OS is broken. Can you acess your bios menu?

Boot into the ThinkVantage Recovery partition during startup by pressing the blue ThinkVantage button on the keyboard. See whether the TrackPoint and trackpad work consistently in there. If you don't have the recovery partition, test the problem in this: http://support.lenovo.com/en_US/downloads/detail.page?LegacyDocID=MIGR-6291 Use ThinkVantage System Update to download all the latest drivers, firmware, and updates.

Reinstall your operating system.

reboot the system, wait for the VAIO logo to appear, and then start pressing F8(keys depends on the model ) . The Advanced Boot Options screen will appear shortly. Use the arrow keys to highlight the “Repair Your Computer” option and press Enter.

You would need to reinstall Vista together with the device drivers and programs to get a laptop functioning again.
You need to backup your data before you reinstall Vista but since you cannot boot up and get into Windows, you need to remove the hard drive and connect it to an USB hard drive adapter and then plug it into a working computer's USB port. This computer should see this hard drive as an external hard drive (provided the hard drive is OK). You can now see the various folders and files, copy your data files to a USB memory stick or burn them to a CD.
Insert the hard drive back into your laptop and then install Vista.

In this case you have to do the PC restore . you can do that in dell machines by shutting down the machine and when it is coming back on just HOLD DOWN THE CTRL ket and the START HITTING f11 key in this case you will lose the data which you have the on the c drive but this issue will get resolved .

Else you can try to restart in the safe mode with networking and then go to the system restore and then select the bold dates in which you have idea you system was working fine . selct the date and then do the system restore . In this case you will not lose the data but you will lose the updates which you have done after that date .

in both the cases system will work .

when the computer is booting up hold F8 to go to the windows advanced options menu it will give you options to boot from last known config as well as safe mode

The Acer Recovery CDs do not set the Boot flag on the hard drive. I had to manually set the boot flag to on using GPARTED Live. After restarting using the GPARTED CD, you can manage the flags under the partition drop down and click on the Boot flag. After exiting GPARTED, I rebooted the laptop and no more black screen....fixed!!
I hope this helps others.

You have a virus I hope you have your data backed up. Reformat your hard drive(I assume you have a boot disk)