I signed up to this website last year and I downloaded bootskins, wallpapers....pretty much anything that I liked. Can any of these files damage a PC system or cause viruses/slowing down.
Just a question before I start customizing my new one
No virus worries, or damage, and slowing down depends on what you're downloading I guess
Nope, no problems with viruses or malware in any file (s) downloaded from WC... I've been downloading from here for 5 years and have never encountered anything bad in any of the skin files... ever.
So yeah, download to your hearts content, safe in the knowledge that all files are clean.
All the files here are checked by moderators before being made public. It's something other sites lack and is one of the benefits to downloading from WinCustomize.