i deleted some wrong files with my hijack this program

my os is windows 2000 i downloade hijack this & ran the program then deleted some files that shouldn't have & now when i turn on my cpu it freeze up then i press ctrl+alt+delete it indicates that WAOL is not responding then i press end task after that my computer indicate that my mcafee anti virus is missing files. i know other files are missing because when press ctrl+alt+delete all the info that use to be their isn't PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

HijackThis creates a Backup folder where you installed HijackThis. Open HijackThis and you should see one of the selections "View the List of Backups".

i looked in the view the list of backup & nothing was there. thanks for the info even though i didn't sole my problem. do you have any other solution

You can use windows sfc (system file checker) You'd need your Windows CD to make this work.
Click Start> Run> type sfc /scannow Note the space.
(Note that there is a space between sfc and /scannow)

This will fix missing / corrupt Windows files. If you deleted other program files this won't help.

thank you, i was hoping that this would solve my origonal problem. when i turn on my cpu it freezes while the files are loading, & when i press ctrl-alt-delete it indicates that waol is not responding then, when i highlight waol is not responding press end task my cpu continues loading as normal. it all started when i ran the highjack this program. thats why i thought maybe i deleted some files i needed, also in the section that pops up after i press ctrl-alt-delete there were less programs\files shown. i could really use some help.

Re-install WAOL.