OK firstly about now - go to your \program files\emule folder and find a file called downloads.txt - open that and see what links you have in there. If you are lucky, you will have all the hashes still in this file. I back up this file ANY time I make significant changes to what I am downloading, and so far, have only "lost" about one film (touch wood). If this does not work, you are going to have to look at a program which can recover .part files - be aware that any that were actually being accessed at time of crash are probably corrupted and would have to be re-downloaded. I have had very limited succes with a program called MetFileRegenerator.
The other thing you can do is invest in a small UPS to prevent power failure from affecting your system (it will shut your system down gracefully on battery power) - probably get one pretty cheaply on e-bay.
Good luck dude - if worst comes to worst, you have all that fun of re-downloading everything
Page file. Right click my computer on desktop (assuming XP), go properties\advanced\performance\settings\advanced and then click on virtual memory and change. Likely you will have a setting which says "let windows manage this" and will be on C drive. What you have to do is try to set this to a fixed value of around 1.5 times size of RAM (e.g. 512RAM=767 virtual, 1G RAM = 1.5 virtual etc), BUT you should pick a drive which has plenty of free space (unlikely to be true of C drive). You then set the new drive to have say 767MB 767MB and click on set. Now reduce your entries on C drive to show 64MB 64MB and click Set (this small amount is to enable minidump from memory in case of crash). These seting were of course if you had 512MB RAM. You are now setting your own virtual memory size and not letting Windows do it for you.
Finally reboot your PC and check it has retained the settings, if so you should see marked improvement and no more "virtual memory" issues.
Other thing you need to do is to stop as many startup applications/processes and services as you can (all load into memory at startup). Do you really need Adobe checker on startup (for example) - probably not. If you click on task manger, see what processes you have running at first startup - alternatively, use Spybot in advanced mode and this is displayed for you - you can even disable startup programs there. If you are not sure what it does, Google the exe or dll.
Lastly, go into advanced settings of XP and turn off all the gimmicky stuff like shadows under icons and caching of icons and shite like that, you will be amazed how much better it will run.
Hope this is useful - pm me if you need more advice.