Getting data from unallocated usb h/drive

Bit tricky to descibe but here goes.

Some scrote came into our garden and took a peice of paved edge which was then smashed outside and part of it thrown through a neighbours car window. Unfortunately for the little bastard he picked the one house in the street with cctv cameras to get his 'tool'. Although the police have been and 'recorded the said footage onto there own device via the video out I would like to retreive it myself before it gets recorded over.
However this is where the problem is, the software provided with the DVR will not work with Vista, I cant find a new driver and the DVR that has the footage only has a USB port which shows up in vista as an unallocated drive. What I need to do is find an app that can view and allow me to copy certain files from the USB of the DVR(which just shows up as an unallocated drive). I dont want to change anything on the DVR's hardrive. Ive tried a prog called 'power data recovery' but then had the thought that the DVR drive is 160Gb while the laptop is only 120Gb total.
Anyone know of such an app?

P.S. Tried just plugging a usb pendrive in but nowt happens.

What's the make/model of the DVR?

Theres no make on the unit (or instructions) Only thing wrote on the bottom is 'Model .41GX'. Its a 4channel DVR, the software that came on the disc is the same as here Version 3.8, wont install on my Vista system.

Try a Hirens XP boot disk or a Linux Live Cd.You never know as the DVR looks like it may be Linux.

Or see if you can find an ext3 driver for vista?

Did you get anywhere with this?

Sorry for not replying, tried looking for the ext3 driver with no luck, tried ext2 driver (i think) that didnt work either. I have got the Hirens boot cd but aint tried it. I got some data recovery prog that turned out to be a virus thankfully my Nod stopped it but when I ran another app that ran but done nowt. I was then convinced I'd just ran another virus so after a full virus scan (2 hours) I was a bit pissed off and gave up on the idea.
I managed to assign it a drive letter but everytime I tried to open it the comp just says the drive requires a format, Format now? Y/N.
Might try the boot cd after the new year, everytime I try summit now I just end up in a mood.