I just recently did a system restore of my PC and now I can't run the mods I've downloaded. I've reinstalled SC a number of times but the mods refuse to work.

So does that mean I need to download new ones? Or is there some other underlying problem at work? Please help!

Disable DEP (Data Execution Prevention) and UAC (User Account Control).
If you're unable to do those things, you're not the administrator account, which is the problem. If you still can't run mods after disabling both of those and restarting, the problem likely stems from the executables themselves and I would recommend redownloading the mods.

If you used Blizzard's downloader to install StarCraft, you will likely need to use regedit to create appropriate entries that point to SC's root folder.

Pr0nogo: so that means I need to access the regedit or the task manager to do that?

Sand Wraith: could you show me how to do that? just in case I need to follow your method. I'm a little at lost with maintenance of Windows 7 :S

Just google 'disable UAC in Windows 7' and 'disable DEP in Windows 7'.

Well, I can't seem to find the install path of my SCBW installation in my registry, so you'll probably have to google it. Just google something like "Starcraft install path registry".

You shouldn't really need to disable either of those things to run SC mods. Instead of turning off UAC, fix the permissions on your Starcraft folder, if you don't know how to do that, an easy alternative is to just install it somewhere else that you can write files without being in admin mode. As for DEP, the older mod loaders that are incompatible with it operate on SC versions that don't opt-in for it anyway and if you have up-to-date versions of the current stuff, it should be compatible with it since the authors have been more aware of it, probably all having systems of their own that use it, and have changed their code to assign the proper memory access types to be compatible.