Deleted system files

I deleted system files (put system files in trash) accidentally when trying to clear my macbook. (I am unsure which model. Was a hand down from elder sibling. I believe it might be 2007 or 2008) When I start it up now, it shows the apple logo followed by a cancel sign and it switches between those symbols while ever so often showing a folder symbol. I know this was an immensely stupid thing for me to do. I do not have the original OS disc around but it seems I have a disc stuck in there and the eject button won't work properly anyways. The computer was working fine before it, so that is literally all that is wrong with it.

I have 3 main concerns

1) Is it possible to restore the system as if I never deleted the system information? And if so how?

2) If there is no way to recover the system is there an inexpensive way to recover the files left on the computer?

3) Is there a time limit before files are lost?


If possible please respond quickly as some very important files that might be due soon are on that computer!

Thank you,
Jim

 

By chance do you know how up to date OS X was?
You can try Recovery mode: https://support.apple.com/en-us/HT201314

If it boots up you can install a clean copy of OS X but keep your user files intact. (do NOT choose erase HD option)

Do you have access to another Mac? If so you can attach the 2 and recovery the files by starting the problem Mac in Target Disk Mode: https://support.apple.com/kb/PH10725?locale=en_US

No there isn't a time limit before files are lost.

 

Ans 1) Did you have Time Machine backup of your system? You can restore your entire OS X through Recovery Mode. Alternatively, a clone copy can also restore your system back.

Ans 2) The non OS files such as word, text, ppt, adobe and media files can be recovered using Mac file recovery software. Once you restore your system back you can run free scan using Mac file recovery software

Ans 3) It is difficult to restore files that are overwritten by new files.

Let me know if you have further query.