When it boots, you will get MUCH more than a command prompt. You will get a fully functioning operating system - file manager, web browser, office apps, etc. You will have to "look around" a bit because it is not Windows - the file structure is different, the commanad prompt commands are different, but you will be able to do it.
I don't really have the time to search now... You have to find an adapter for a laptop hdd (2.5") to a 3.5" bay (for a desktop computer). After that, the method I consider "the most easy" ("easier" it's the word? Or "easiest"? I don't know...) is to move your laptop hdd to a desktop computer and to do there the backup and try to find viruses and spyware on your laptop harddisk.
If you HEAR now for the firs time of Linux it will be a little more DIFFICULT to use it.
If you have a DSL access line, you may use without regret the http server to download the ISO file, it is a very good internet connection. But, large files still last a lot of time to download. For example, I have a connection (at work) of 512 KBps-1MBps (that's more than your connection could offer) and still took me 5-6 hours to download 700 MB. And the transfer speed depends also on the remote server network speed also, not just yours (the transfer speed will be the the smallest transfer speed between your computer and that server). I'll rather sugest you to find a magazine with a linux live cd or linux live iso image on it's cds. From there is simple: copy the file on hdd and create a new cd from that iso file. If you have to recover your data quickly, use the "Windows" method - move the hdd to a windows machine and let Unix/Linux be a hobby for some other time.

How would I do if I would have the same problem:
1) place the laptop hdd into another computer, as the second hdd; that second computer has to have Windows XP
2) backup the important data; if there are secure files (encrypted files) than do a backup of the full laptop harddisk. That is the most important step. Don't do anything to that hdd if you don't have a backup! You can loose all your data...
3) try to find viruses on laptop hdd
4) try to find spyware on laptop hdd
5) If you have the backup of your hdd, try to restore windows xp on that laptop hdd. How? Place the hdd back in the laptop. Boot with Windowss xp boot cd and choose repair option (don't ask me how... find a book, ask a "small expert" - but be sure he/she is an windows recovery expert. I don't know how to use windows xp repair options... I should know, but I don't know ).
If it doesn't work the repair, reinstall windows (with no repair) over the "old" windows... But I don't recommend you, it is possible to mess the things more than they were.
If you mess something up, use your backup to restore your laptop hdd. You have to be very carefull with your backup, to not destroy it.

If you have the backup of your hdd (be sure you have it and it's "ok") you have more chances to repair your data. If you don't do a backup, you have only ONE chance to recover your data. And only ONE!
Tell us your option, and also if you solved the problem.
If you don't understand a single THING of all of that, ask! It's your data we are "playing" with.Sorry for the DELAY in replying.  I've had some broadband DSL issues as of late and put the Compaq repair on the back burner.   As an update, I did order an USB laptop HDD enclosure for $10 from the internet.  If anyone is curious, I priced a similar layout, selling for $19.99 plus tax (on sale from $39.99), at a major computer products retailer that I like to shop at [I won't mention names, but there is an acronym in it's title].

Since I'm not brave enough to experiment with Linux, I'll go with Viking's advice.  I am curious about Linux, though!  GX1 mentioned that Linux would just boot up to a windows-like environment which sounds like it is what I need to jumpstart my Compaq.  I am just scared to lose all the data on the Compaq, which is why I am not going with Linux, just to be on the safe side.  With that said, I will hook up the Compaq's HDD inside the enclosure, attatch it to a USB port on a working computer, then run anti-virus software on the USB HDD.  I downloaded the program ewido, which I like a lot!  Would that program be sufficient enough to check the hard drive?Ewido checks for trojans, hihjackers, worms and some spyware.  If that's not the problem, Ewido is not the solution. Keep us posted on your progress.