Following an encounter with many of my old DOS favourite games, I've been trying to finish some of them, that didn't have an "ingame save option", using DosBox's feature of quick save/quick load.
Unfortunately, the DosBox works fine until one point where it crashes and you cant go back, reload, start the same level or anything. You have to start over.
I've been recommended here to use Game Wizard, as it might have the same functions, but it's not working on my Windows XP SP3. Is there any way I could make the Game Wizard program work properly or any alternative to it? I just want a software/emulator that helps me save my dos game progress.
I know that DosBox's feature is in-progress and it might take a while, could you please suggest any alternative?
Much obliged for any suggestion

Never heard of Game Wizard O.o
DOSBox hasn't crashed on me - but it depends on the game, the .conf file settings, and the build of DOSBox being used. Does it crash for you on save stating/loading a save state/randomly/etc?
Might wanna go to the DOSBox site and check the bug tracker or search for a DOSBox games list to see if the game(s) you are having issues with are listed somewhere w/ workarounds.
I have found DOSBox to be the most effective at running most DOS games, sometimes using a Virtual Machine w/ an installed copy of DOS (either an MS variety or FreeDOS) will help too [I recommend trying out VirtualBox [Oracle Systems - free software app] with FreeDOS/MS-DOS]

I've downloaded and istalled virtualbox from oracle, but I don't know how to actually play my game in there. It seems to have an option only for CD's, where I have the dos games on my hard drive

You need to create a new VM w/ the wizard - this will create a virtual hard disk. Then use an install media (you can download a FreeDOS CDROM image from the FreeDOS site) to install an operating system. To ease the transfer of install files/game files you already have downloaded you can use utlities to create a pseudo CDROM/Disk image.
Or, alternatively, you can try downloading a pre-made VirtualBox image and doing a google on how to do the rest: http://virtualboxes.org/images/

It's an unofficial, experimental, third-party build that I linked to here. On the forum the author says that in his experience, it works for some games, but not for others.

That would explain it.

Savestates are for pussies, real gamers don't need'em. Well, at least until you have to deal with some nasty bitch the likes of Syndicate - American Revolt, of course :-P