Here is the list of dangerous things a spyware or ad-ware can do

a. Spyware can track your online purchase and also your credit card number
b. some spyware logs your keystrokes and finds the password for bank account number
c. spyware can send emails from your account to your email contacts
d. spyware can help remote hackers hijack personal information
e. They can easily infect exposed PCs over dial-up or broadband connections
f. spyware can make changes to your computer and cause your computer to crash
g. Spyware can change your browser home page or search page
h. It may install program without your knowledge
i. It can download programs from internet in background
j. It can block or delete some programs from your computer
k. It can cause damage to important files on your pc
l. Spyware or ad-ware can display annoying popup ads while your are surfing
m. it can also add internet shortcuts on your favourite folders without your permission

Can the spyware be removed?

Yes it can be removed by spyware remover program. Spyware remover program searches the computer for possible spyware and remove them instantly.

For more information regarding spyware or antivirus visit
Anti-virus software Reviews | Stop Spyware