Ok many people tend to end up getting emails that have hidden stuff. Most times it has hidden adware. Gator and other crappy programs are still out there and still being passed around in what seems to be legit emails. This will happen alot it is hard to stop it all so you must be prepared.
So here are some free programs to get that you can use to help protect you.
1. Anti Virus Actualy one of the best ones out there is free, its AVG antivirus. Get this unless you have a payed A.Virus program you already use. All tho having this as a secondary is a good idea. Since no one A.Virus program can catch it all.
2. Get adware, its free and it takes care of ads and trojans the anti virus programs can not get. also spybot search and destroy is a good one but may no longer have a free version.
Remember even with these in their payed versions there is no gaurentee it will clean everything. However if all goes well they will at least ID what is on your system, then you can google the exact name it catchs. Then goto the mcafee or norton semnatic websites to get info on manual removal.
You can also look at your browser and see if it has a built in popup blocker, if it does i would engage it untill you have cleaned your problem. it will help some if your having pop up issues. Once you think you have cleaned out your problems then you can take your blocker back down or just leave it and set it for websites you trust.
Virus and adware is very bad, so are tool bars from websites. Most times you might find them in your add/remove programs folder installed for no reason, if you find them, go ahead and remove them with the uninstall that is there.
Be very cautious when doing any manual removal of adware and spyware on your system, be sure to follow any directions you are given and do backups prior to the removal. its always best to revert back if you make a mistake then it is not to.