Installing Mint
 

I downloaded Mint and burnt it to a CD. The computer boots up fine with the CD, goes to the Mint home screen, but when I try to install it and partition the hard drive to run next to Windows Vista, the screen completely garbles (green background with short different colored horizontal lines all over it). Is this normal? Should I let it run for a while and it will clear up? How long can I expect the partitioning to take?

I did not have this problem installing Mint along side Windows 7, but I was able successfully to avoid Vista in all its manifestations, but, no, it does not sound like normal behavior.

In my case, though, Window 7 was already using all four primary partitions (I think Windows did that just to be irritating). I resized the largest one, then created an extended partition; I then installed Mint to extended partitions--Linux installs quite nicely to extended partitions. I had to use the manual partitioning option in the Mint installer to do this. Having to be on a primary partition is strictly a Windows thing.

As for how long partitioning takes, not long. Resizing an existing partition can take quite a while, as can the formatting, depending on the size of the partitions. (Note that, if you must resize a partition, you should back up all crucial data first--the process usually goes smoothly, but there's always a chance something can go awry.)

What is the current partition structure on your Windows machine? Knowing that might cast some light on this.

Well, in short, that appearance can be 'normal' while it sorts out the graphics. I would be more confident if you said you had checked the download against a md5sum test and variefied the disk burn, many burning programs will do the later. Windoze does not come with a md5sum checker by default (or many other programs, for that matter) but you can get one from a reliable (ish) source.
That said, once you get to the start page on the Mint cd/dvd you can usually try the 'live' option without affecting your Win. installation but helpful to see if you like Mint and if it is compatable with your hardware, patience with the funny lines.
Before you get to the partitioning, you will have to go through several pages/windows and even when setting up the partitions you will go through some options and then it will ask you if you want to write it disk/hdd.

Fred.

Did n't read (see) Frankbell's reply. If you get the strange behaviour once you have done the partitioning then, it might be you have run out of primary partitions, if so send info on your current partitions.

Fred.

I'm not clear on the status of the install from the OP as to whether this suddenly happens while he is trying to partition from the installation medium or after install. If it's the latter, it's pretty common and I've experienced this with my machine with nvidia graphics with the last several releases of Ubuntu, Mint and some derivatives. Usually, the install medium works fine but after the install on boot comes the garbled screen and putting nomodeset on the kernel (linux) line on boot allows a one time boot to get Additional Drivers for graphics. Selecting the second optin on boot after the install (Recovery?) usually does the job also.

Problem Solved
 

Thank you for all your responses and suggestions. I have learned through other forums that Microsoft Vista in some incarnations will not allow another operating system to be installed alongside it. I am sure this is the reason for my problem. I'm not sure if I want to do it right now, but I will have to re-format the hard drive, thus eliminating Vista before I can proceed with Linux Mint on that particular desktop. For now I will say problem solved.

This makes no sense to me. How would a windows install sleeping on another partition be able to interfere with the graphics of a running live system?!? Can you provide a link to a site where this phenomenon is explained?

I'd be reasonably confident that this is not your problem...

I did see some graphics issues sometimes in Mint live systems. It would be worth trying to install anyway and see how works once installed. Some previous posters gave good advice on how to proceed, too...