Photoshop

Yes... If you download a torrent of adobe photoshop, its free. Inkscape and GIMP is free photo editing softwares.

You can download portable Adobe Photoshop from the internet. With the portable version you wouldn't have to install the software, you can immediately use it anytime after you've downloaded it or extracted the file if ever the downloaded file is zipped. You can watch videos from Youtube on how and where to download the portable versions. I suggested this to you because if you would ever download the real/ complete software, whatever you call that, the file is really big in size while the portable ones doesn't really need big memory spaces.

The best free program which has about 95% of the functionality of Photoshop is Gimp: http://www.gimp.org/downloads/ Even though they don't 'officially' produce a Windows binary, the GIMP 2.6.12 – Installer for Windows XP SP2 or later is trouble free and works.

There are some online photo editors, for an example I use the lightshot program which is a printscreen program but whatever you take from your screen you can edit it online.

Use gimp, it's a good alternate to photoshop and it's for free. Find the download link in there website http://www.gimp.org/ Hope you find gimp a good alternative ....