Ah
just read u r using ShadowLite. Try a regular sync and that should sort you out. I dunno if u gotta re-download blockchain or not. Pop in IRC for more extended support if u continue to have probs.
Regarding backup: Copy the wallet.dat to a USB stick. When restoring simply replace whatever wallet.dat file the new wallet generates with a copy of your one making sure the shadowcash wallet is not running at the time.
All right, so backup wallet.dat, close wallet, wipe everything else in ~\AppData\Roaming\ShadowCoin, restart wallet and copy over my wallet.dat?
Sorry for such a noobish questions, but these instructions aren't available @ SDC wiki or else.. it might be a good idea to post a few of these "tutorials" for newbies is SDC wiki open to such submissions?
As you said but no need to delete wallet.dat before replacing it since you're not moving your wallet between computers.
SO (what I would do)
1. backup ur wallet.dat to a USB stick
2. quit SDC wallet if running
3. delete everything in app roaming except the wallet.dat
4. restart shadowcash wallet and wait for a regular sync
Did you check shadow.cash for tutorials? It already has some. More always good

note: The sync is slow but this issue has been addressed iirc and will be MUCH faster in a future wallet.