i turned on my laptop this morning it shows me loading windows but after that before any login screen the screen just goes black and has a white cursor on it. the computer will not let me try to boot into safe mode.
There are many causes for this black screen hang, it can be anything from a corrupt graphics driver, bad hardware, or file system corruption within the $Txf directory.
If you try Safe mode and get the same black screen this will rule out a corrupt graphics driver.
I would run a chkdsk on the hard drive by booting from a Vista or Windows 7 DVD and load command prompt to run
Then see if it will boot or attempt startup repairs after chkdsk has completed and you have restarted the PC.
If you suspect the $Txf folder is corrupt, you have two options,
Step 1. Boot the SystemRescueCD disc, answering any localization questions as required, until you get to a shell prompt.
Step 2. Mount your hard drive at /mnt/windows using ntfs-3g, e.g. "ntfs-3g /dev/sda1 /mnt/windows". You may have to "ls /dev/hd*" or "ls /dev/sd*" or "fdisk -l" to figure out the correct device to mount. If you are using a RAID device for your root file system, run "dmraid -ay" to attempt to mount all available RAID file systems, then "ls /dev/mapper" and look for your device. Also, if the NTFS file system is corrupted (which it probably is if you are reading this post) you may have to add the "-o force" flag to the mount, e.g. "ntfs-3g /dev/sda1 /mnt/windows -o force".
Step 3. Verify that you have the correct file system mounted by "ls /mnt/windows". You should see the content of "C:" or whatever is your boot drive in Windows... if you don't, repeat Step 2 until you mount the correct device.
Step 4. Navigate to the first hidden folder: "cd /mnt/windows/\$Extend". Note the backslash before the $; that is important as it keeps the command shell from interpreting the $ (it is really part of the file name).
Step 5. Navigate to the second hidden folder: type "cd \$RmMetadata". Once again, note that the $ is escaped with a backslash.
Step 6. Type "ls". Among the files/folders listed you should see "$TxfLog". Take a deep breath and recursively remove the $TxfLog file: "rm -rf \$TxfLog". Once again, note that the $ is escaped with a backslash. Use "ls" to verify that it has been deleted. (You should see the same listing as in Step 6 except the $TxfLog folder is now missing.) Type "cd /" Type "umount /mnt/windows" to cleanly unmount your NTFS filesystem. Type "init 6" to reboot, removing the CD when appropriate.
At this point, your system still may not boot. To fix that, here's part 2, for which you'll need a Vista or W7 DVD.
Boot the Vista DVD and choose "Repair my computer". When the system looks for Vista installations to repair, it probably won't find any. Don't panic; just click Next. In the System Recovery Options list, choose Startup Repair. The system will process for a minute or two, then state that it needs to reboot to finish its repair. Allow it to reboot. Remove the DVD at the appropriate time and allow the system to boot from the hard drive. If the system complains that it was not shut down properly, choose "boot normally". You may have to repeat Startup Reapir up to five times to "convince" the system to rebuild itself. If the system gets "stuck" during the rebuild process for more than an hour or so, force it to reboot (hit the reset switch or power-cycle the system) and try again.
Try disconnecting peripheral devices like USB drives or printers if connected. Does the laptop have a diagnostic partition that allows you to test hardware? As @jmreicha says, check the drive and other hardware.