XP What program to use when installing patch

[35P3N]

So, Im staying at my moms house for the weekend and decided to borrow my friends laptop (its a PC) with Project reality installed. But it don't have the latest patch installed.

My mom has a slow 56.kbs connection, so i downloaded the patch on my 20 mbit at home, on the friends laptop, using the torrent option.

Now i'm at my moms house and I am trying to install the patch, BUT when im clicking the patch: windows opens up the "OPEN WITH" box and asks me what program I want to use to open this file.

I have no clue what program to use, and windows gives me no useful suggestions, just random programs previously used.. like uTorrent and acrobat reader. And I'm pretty sure those wont work.

My question, in other words is: What program do i use/choose to open the patch?

I realize that this is more of a windows issue than a PR issue, but I've googled it and asked questions on IRC; leading to no resolution. Please help if possible. Im sure it is a simple solution (like choosing windows installer or something), but of course; maybe the file is just corrupt, and I need to download it again. But that will take a loong time, and I would like to try to make it work, because i doubt the file is corrupted.

[35P3N]

For the record: I solved the problem by adding '.exe' to the file name and then installing microsoft.net framework 3, it was evidently missing.

Sadly the internet speed of the 56 kbps is not sufficient, and leads to an extremely high ping.