Concerning iTunes

Let me just state, for the record, that my fight with computers has been an uphill battle. Some background may be in order.

A few years ago, a big ice storm came through KS, and my house lost electricity for several days. My room, with my desktop in it, was particularly cold. After the power finally came back, my computer was never the same.

After a certain period of time, it'd turn off with no warning. This, with a mix of virus problems that never ceased, caused me to stop using the computer for awhile.

Recently, I went into recovery mode (it wouldn't turn on otherwise), ran a virus check, got the viruses off, and for a moment, I hoped.

My hopes were dashed.

My computer's wallpaper and Firefox were gone. It was as if the computer was brand new, but the icons were still there. I double clicked on iTunes, and it said that it wasn't installed. Confused, I went to iTunes to reinstall. It said that I needed to update some kind of installation thing, and so I couldn't reinstall iTunes.

My stupid desktop has been working against me for years...

Is there any chance that my songs, which had been on iTunes, can be recovered? I recently got a Mac Laptop; would I be able to transfer my music files from my windows desktop to my mac? Is there any way to get my desktop back to working condition?