can I copy all my programs on an external drive to run?

No. The vast majority of applications need to be installed on the system drive.

Allan

Generally, applications aren't that big of a HD space hit. The biggest hogs are music and photo files, i.e., iTunes and iPhoto libraries. And they can be easily relocated to an external.

Overall, your best bet would be to just get a bigger internal hard drive.

http://eshop.macsales.com/shop/hard-drives/2.5-Notebook/

I'm not sure if this is what you're looking for, but the following site:

http://scsc-online.com

has a product named Phoenix. It can extract the core OS from a working volume (Including all applicaitions in the orginal install) and put them onto another volume. I don't know if it would really quite fit your needs but it might.

The real purpose of the product is to create an emergency boot volume for their test tool, Scannerz. It's sort of like the eDrive in TechTool Pro, but instead of having just a few OS components, it creates essentailly a clone of an initial install of the OS....in other words, it's a full operating system. The OS is extracted from your working volume, but you would need to manually copy over anything you added after the OS was installed.

It might work, and it's cheap.

Copying and pasting applications in a fair number of cases may fail because by copying you're typically resetting the permissions of files to system defaults (i.e. non-root) which may cause the app to malfunciton. Also, during updates some apps will also expect to see the application in a specific location. It's not true for all apps, but it probably just enough to make life really irritating.

Depending on how involved you want to get you could do the following:

1. Create a symbolic link from the external HD to /Applications after moving the contents of /Applications using ditto.
2. Create a symbolic link from the external HD to /Applications after moving the contents of /Applications using rsync 3 (not the rsync that comes with OS X)

Both ditto and rsync 3 will preserve permissions, resource forks, attributes, etc etc and the symbolic link would be set up to "redirect" from the external HD to the Applications folder. I've done this several times with development directories and even XCode and it works great, but you need to know what you're doing. Cloning tools like Phoenix, Carbon Copy Cloner, and SuperDuper all make use of these commands - that's how they work.

If you're up to doing a little command line work and you're familiar with what I'm talking about, items 1 or 2 above may be an option. Otherwiise you might want to pay attention to the input the previous posters provided since their points are all valid.

Nobody will really be able to look at your hard drive except to replace it and maybe help you pull stuff off, all with a price tag, of course. If it's clicking, it's likely dying and you should try to get as much stuff off as possible.

The company that I linked above has a product called Phoenix that can extract the OS from your volume and put it onto a USB flash drive or another drive, which can be used to re-install the OS. I don't think that's the tool's actual intention. I think it's really supposed to be used to as an emergency boot drive but it can do installs as long as it's the same system. In other words it's supposed to function for emergency repairs and recovery. It can do that and basic volume cloning, so it might be of use to you, but I have no idea if it supports Windows at all.

With that said, however, a 32GB USB flash drive costs about $15-$20, Phoenix cost $13.95, but a new set of Snow Leopard disks only costs $19.95 using this link:

http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard

If you just want the OS I'd just get the install DVDs. If you want to extract it use Phoenix and maybe clone the volume off, but like I said, I don't know if it supports Windows.