Not sure what software or level of deleting you are asking about.
the recycle bin is a big "safety net" on the windows desktop
it works on a last in last out basis ... so when it's fullthe oldest files are deleted permanently to make room for the next batch.
To undelete - right click on the bin | explore | find the file(s) right click the file(s) | restore ....!
(clicking properties will allow you to increase, decrease or disable this safety feature)
If deleted using a command prompt or bypassing the recycle bin .. you will need something like O&O undelete .... or if you use norton ... the protected bin feature will do the job.
in all cases
you need to stop using the system IMMEDIATELY you realise what you've done because if you continue windows just might save another file into this "free" space ... and then your old file is effectively gone for ever.