Welcome to Seven Forums Sara11.
I misunderstand, you did or did not click Save Changes?
You can try Right-clicking an empty place on your desktop and see if there is an "Undo" option listed.
Also open notepad and click the floppy icon in the upper left, it should show you recently opened documents, if the one you want is there, click it and it will reopen.
My Computer
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Home Built Desktop By DataTech
OS
Windows 7 Ultimate X64 SP1
CPU
Intel i5-2550K, Differing ~4.4-4.8GHz No built in GPU
Motherboard
ASUS P8Z68-V PRO/GEN3
Memory
16GB G.Skill Sniper 1866MHz @ 2133MHz 2x8GB
Graphics Card(s)
ASUS GTX650TIB-DC2OC-2GD5, (650TI Boost)
Sound Card
Onboard Realtek 5-1
Monitor(s) Displays
Samsung P2570HD
Screen Resolution
1920x1080
Hard Drives
Samsung 840 Pro 256GB SSD for OS, 500GB Seagate Constellation (Enterprise drive) for Data
PSU
Corsair HX650W
Case
Inwin Dragon Rider
Cooling
Hyper 212 EVO w/two Noctua fans, push-pull, @1300 RPM
Keyboard
E-Z Eyes, bright yellow keys with large characters
Mouse
steelseries SENSEI Laser Pro Gaming
Internet Speed
48-51Mbs Mbs down, 11 Mbs up Xfinity Cable
Antivirus
Norton Internet Security 2013
Browser
IE 10, Opera, Pale Moon if needed
Other Info
4 case fans, LG BluRay-RE, ASUS DVD-RW, Mr. Fusion power supply, 1.21 gigawatts.
It's free and lets you get old versions out of restore points.
That is if you made a restore point since you made the file.
Other than that on Windows you need an editor that makes multiple backups with version numbers.
The old Vax/VMS file system did it automatically no matter what editor you used. But no other file systems I'm aware of seem to want to copy that feature. Don't know why not since it can be a bacon saver.
My Computer
Computer Manufacturer/Model Number
HP Media Center
OS
Windows 7 32 bit
CPU
AMD 5200+ dual core
Memory
2 GB
Graphics Card(s)
NVidia GeForce 6150SE 128 MB
Monitor(s) Displays
CRT
Screen Resolution
1280x1024
Hard Drives
500 GB Sata internal :
SIIG USB 3.0 docking stations w/WD Caviar Black 6 Gb/s drives