Can files encrypted by virus be read?

Question

virus encrypted many files [ppt, cdr etc.] they are not accessible. Can it be possible to access them?

Answer 1

No they cant be read, if they are encrypted. Try dragging and putting that file to a notepad and see if it is normal text format.  

Answer 2

I doubt they are really encrypted viruses mostly modify what's called the file header. If they are not accessible you could try a proggy called unlocker (google is good) then get a hex editor available from download.com now you can check what's up sorta kinda you could also use ollydbg which would provide greater clearity but you gotta know what your looking at and the learning curve is pretty steep, still it's pretty cool to check out viruses with olly. Oh yeah have fun!