0xc000000f boot selection failed

The error you are getting on your windows is because of the missing boot.mgr file. It could be damaged or corrupted. Now either you have to install a fresh copy of windows or initiate a startup repair.

Read the full solution here -

windows Error Code 0xc000000f Solution

if u can login via f8 safe mode and select command pronpt u could try and repair youre boot sector c:/fixmbr or c:/fixboot but u must have admin privilages or check out below then run cd dvd to reinstall
http://www.sevenforums.com/general-discussion/17521-how-fix-mbr-through-command-prompt.html thanks

Sometimes updates can cause problems with the OS and thus using the Repair potion of the Operating System Disc is necessary. You may have re-install the operating system again. The problem, if you did not back up the drive, you will loose all data and programs.

Try first getting in via safe mode (Hit F8 when booting and then choose Safe Mode) - then use system restore to revert to a previous working state.

aspire aspire d257 status 0xc000000f Info: the select entry could not be loaded because the application is missing or corrupt

Sounds like your hard drive has is failing. You will need a clean install of your operating system! It may also be that your hard drive has failed completely with knackered sectors. Now would be a good time to buy another hard drive. They are pretty cheap on ebay.

You're getting that error message because the boot files on your hard drive (the required inaccessible device) are corrupted.

When first booting, press F8 repeatedly. Will the computer let you go into safe mode? If not, without the installation cd, you're kinda between a rock and a hard place. However, you can download a (free) vista recovery disk (repair only) from the people at easyBCD:
http://neosmart.net/wiki/display/EBCD/Recovering+the+Vista+Bootloader+from+the+DVD

Just follow the directions to do a start up repair.
If that works, by all means, make yourself a recovery cd before doing anything else.