Hi S2K:
I've run into this problem before with older Inspiron's. The real problem here is that you have changed the original Windows OS from Windows XP Media Center Edition 2005 or earlier to Vista. If you got the laptop in 2008-2009 and you admitted you weren't the original owner, that's why you didn't get the discs. Someone upgraded it and didn't include those--amateur!
I ran into a similar problem earlier this year with a Sony Vaio circa 2005; and it took me like 7 weeks to rebuild it. It's a long story, but, if your Inspiron has a sticker on the keyboard surface somewhere that says "Vista" ready, the Vista you have on there should work properly. That is if it was installed correctly, and from everything you have indicated it wasn't.
First of all, only a few manufacturer's provided a Recovery Partition for Windows XP MCE 2005; and as far as I can tell, Sony was one who did not. I've seen eMachines and 1 or 2 others who have; but most did not. If you call Dell for the Recovery Media for this laptop, chances are they don't have it any longer. Dell and most of the big guys don't archive Recovery Media sets older than about 4 years or so. Occasionally, you'll get one that's 5 or 6 years old, but only if it was a very popular selling model. The Inspirons were/are very popular, but like I said it's doubtful they still have it even in Archive form.
To answer your cost question; Recovery Media sets run from $15-$99 from Dell and just about anyone else. And, Yes, you can call them to search for the Set for your Model laptop. I order these all the time from them.
If you are lucky enough to get the Recovery Media, and install it you will then find out if your Inspiron model originally came with a Recovery Partition or not, as it will attempt to format your hard drive, wipe it clean (make sure to answer "YES" to this question if it asks you to wipe out the current Partition Table on your hard drive), and then it will recreate all partitions that were on the laptop when it came from the Factory ("Out-Of-Box, or OOB condidtion"). This most likely will include a Dell Diagnostic partition with which you can test your hardware such as hard drive, CPU, RAM memory, etc.
If you aren't lucky you'll have to look at doing a Custom rebuild to Vista; which will completely bypass the WindowsXP MCE 2005 factory build. This can take some skill, and usually takes me several weeks to accomplish; but I've been doing this for 26 yrs.
What you will need is to buy a Full Box Version of Windows Vista *Home Basic, Home Edition, Ultimate, Professional* whichever one you had on there from the person you bought or got your laptop from. This can cost anywhere from $80-$150 on the web as you can only buy Vista there, it's been out of retail stores since 2009 when Windows7 replaced it.
The other thing you will need is to go to support.dell.com and download all the Windows Vista Drivers for your Inspiron. Most importantly you will have to do a
BIOS and CHIPSET upgrade to that Inpiron in order to get Vista to work correctly with it, and without the *Vista Ready* sticker I mentioned above, it's only even money that it will work at all. Also, the BIOS and CHIPSET flash upgrades are
VERY HIGH RISK to do! If you have never done them before, I don't suggest you make this your first time. On the other hand, you sound knowledgeable to you can try--be aware though if you do it wrong you can "brick" your Motherboard and wind up replacing the most expensive component in that laptop.
I Post this with the Hope that you get lucky and Dell will sell you an Archived Recovery Media set, and the last half of this you won't have to worry about. However, if you have built computers for a while, I would strongly urge you to do the BIOS & CHIPSET upgrades prior to applying the Recovery Media set. Especially since you intend to bring it back up to Vista level.
If you have any hesitation in doing this, STOP!
and take your laptop to a local Computer Pro who is licensed and can do this for you. This process is for the Advanced User only. I'm not saying you are not; but, if you haven't done this many times before you might be looking at a $200-$300 repair on an 8 year old laptop--probably not worth it since you can buy a brand new Chromebook for $249. The other thing you haven't addresses is the state of your internal hardware, Mobo, RAM, Hard Drive, and CPU/GPU. Those should all be tested before you attempt this upgrade, as reinstalling from Recovery Media Set or from a Boxed Windows Vista CD will still not operate correctly if you have a faulty hardware component. In a second-hand laptop of that age, the likelyhood is statistically significant there is at least 1 failing or faulty component. And once again I am back to taking it to a Pro if you are not comfortable with or know how to run all the complex tests I'm talking about.
Hope this provides some insight and direction for you.
Post back if you need further advice!
BIGBEARJEDI