Reinstall Network Files w/o completely reinstalling Windows 7?

I am experiencing frequent hangs, and after checking event viewer I'm noticing many network-related errors (Events 6000, 7001, 10005, 7026, 7036), many stemming from services not starting. I was having all sorts of weird trouble about a week ago, and (not very wisely) got impatient and ran a few virus scans and fixes. I've tried manually going through and making sure all services are set to automatically start, but it hasn't helped.

I have a feeling that in hastily running these virus "fixes" that I probably deleted some important network-related files. I've tried returning to an earlier restore point as well as running a "repair" of Windows 7, but that hasn't helped. Is it possible to reinstall only the network files? I'd like to avoid having to reinstall all of my other software again.

(I've never uninstalled all of the network protocols and then reinstalled them -- and am not sure that these files are the ones that I've messed up...)

Things run very smoothly if I disable my wireless connection.

(I have tried updating my wireless driver.)

Thanks.

alliemack

Windows 7 Ult. 64 bit (updated regularly)
Gigabyte GA-MA790XT-UD4P motherboard
AMD II x4 620 Processor (2600 Mhz, 4 core)
4 GB ram (G.SKILL 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
ATI Radeon HD 4600